It is important to understand that no jiva-souls originate from the impersonal Brahmajyoti as those with a poor fund of knowledge foolishly believe.

The jiva-souls have no origin and have always existed without beginning or end as Bhagavad Gita As It Is correct 1983 edition Chapter 2 text 20 reveals-

"For the soul there is neither birth nor death at any time. He has not come into being, does not come into being, and will not come into being. He is unborn, eternal, ever-existing and primeval. He is not slain when the body is slain." (BG Ch 2 text 20)

The jiva-souls who enter the impersonal brahmajyoti, the Body of Maha-Visnu and tatastha-sakti in a dormant state, have fallen to that condition, they do not originate from any of them. 

From where they are generated means from where the jiva-souls are existing in an inactive or dormant state. 

Therefore "generated" does NOT mean "originated." 

Other foolish sangas and their gurus can't understand this fact.

As said above in Bhagavad Gita As It Is ch 2 text 20 there is no origin to the jiva-souls because they have eternally existed throughout all infinity.

Srila Prabhupada explains here the jiva-souls do not originate ftom the impersonal brahmajyoti- 

Srila Prabhupada - "Those who are in the brahman effulgence are also in the fallen condition, so there is no question of falling down from a fallen condition. 

When "fall" takes place, it means falling down from the non-fallen condition (which means Goloka Vrindavana or the Vaikuntha planets) The non-fallen condition is Krsna consciousness."(Letter to Revatinandana, LA, 13 June, 1970)

Srila Prabhupada - "In the broader sense, everyone comes from Krsnaloka (Goloka-Vrindavana). When one forgets Krsna, he is conditioned (nitya-baddha), when one remembers Krsna he is liberated (nitya-siddha)." (Letter to Mukunda, June 10, 1969)

Srila Prabhupada - "There are two kinds of marginal living entities: nitya-siddha and nitya-baddha but the actual constitutional position of EVERY marginal living entity is NITYA-SIDDHA." (CC lecture, July 13, 1976) 

Srila Prabhupada - "By following the rules and regulations and instructions of the spiritual master, he can become again NITYA-SIDDHA. So the Krsna consciousness movement is to make the nitya-baddhas again NITYA-SIDDHA." (NY City Lecture on CC, July 13, 1976)

Srila Prabhupada - "So the Krsna consciousness movement is to make the nitya-baddhas AGAIN NITYA-SIDDHA, to bring them back to their original position. It is a difficult task." (London lecture on BG, 13-14, July 14, 1973)

Srila Prabhupada - "The spirit soul is NOT formless; it has got form, the spirit soul always has form and is expressed as hands, legs, heads, everything. But with our material eyes at the present, our gross eyes, we cannot see these facts; therefore we foolishly believe the jiva-souls have no form." (Lecture on BG 2.14 - Mexico, Feb 14, 1975)

Girl devotee - "What is the form of the spiritual body. If the spirit soul is non-material, what is the form?"

Srila Prabhupāda - "There is form, just like this material body is compared with the dress. Now, just like in your present material form you have got hand; therefore your coat has got hand. You have got legs; therefore your pant has got legs. Therefore it is to be assumed that the spirit soul always has got form, and is expressed as hands, legs, heads, everything. The spirit soul is not formless; it has got form. But with our material eyes at the present, gross eyes, we cannot find it; therefore we say and foolishly believe it has no form." (Lecture on BG 2.14 - Mexico, Feb 14, 1975)

Srila Prabhupada - "Your question about one's relationship with Lord Krsna on Krsnaloka, does he ever fall down? The jiva-souls are endowed with minute independence as part of their nature and this minute independence may be utilized rightly or wrongly at anytime, so there is always a chance of falling down by misuse of one’s independence." (Letter to Jagadisa dasa, 4/25/1970)

Tatastha-sakti refers only to the jiva-souls already in a fallen state, who are already fallen Prabhupada has explained.

The jiva-souls do NOT originate from tatastha-sakti, it refers to those jiva-souls who have fallen to the material creation, and those who have further fallen to the impersonal Brahmajyoti.

It is not possible to originate from an already fallen condition therefore the jiva-souls did NOT come from the impersonal Brahmajyoti as the less intelligent believe.

In other words, tatastha-sakti does not describe those jiva-souls in their original "none-fallen" position in Vaikuntha and Goloka Vrindavana.

Tatastha-sakti is a name describing the none Krsna conscious condition of the fallen jiva-souls.

Srila Prabhupada - "So this material world is the taṭastha (conditioned) characteristics, and the spiritual world is the "personal" characteristics. So our effort is to get out of this taṭastha (conditioned) characteristics and to enter the permanent characteristics. That is called spiritual elevation." (Lecture on CC Madhya-lila 20.354-358 — New York, Dec 28, 1966)

Srila Prabhupada - "Because the individual soul is apt to fall down sometimes under the clutches of māyā, it is called taṭastha-śakti. Just like in the seaside the shore, the beach, sometimes you see it is covered by water and sometimes it is land; similarly, when we are covered by māyā, that is our jīva-bhūta stage, and when there is no more covering, that is brahma-bhūta stage. When we are Kṛṣṇa conscious, then we are brahma-bhūta (SB 4.30.20), and when we are not Kṛṣṇa conscious, we are materially conscious, that is māyā." (Lecture on BG 7.4-5 - Bombay, March 30, 1971)

Revatīnandana - "Srila Prabhupāda you very clearly explained to me once in a letter that if the jiva-soul then goes into the brahmajyoti, he is considered still fallen. Still fallen. Does that means the whole brahmajyoti is composed of fallen souls? You see my question? If I go there, I'm a jīva-soul, and I go to the brahmajyoti I'm still fallen."

Srila Prabhupāda - "Yes."

Revatīnandana - "That means all jīva-souls there in the impersonal Brahman (Brahmajyoti) are also fallen souls?"

Srila Prabhupāda - "Yes, existence in the impersonal brahman is also within the category of non-Krsna consciousness. Those who are in the brahman effulgence are also in the fallen condition, so there is no question of falling down from a fallen condition. When fall takes place, it means falling down from the non-fallen condition (Goloka-Vrindavana and Vaikuntha). The non-fallen condition is Krsna consciousness.'' (Letter to Revatinandana, Los Angeles 13 June, 1970 and 1971 London)

The full potential and original feature of all marginal living entities (jiva-souls) is a two arm form like Krsna's Body Prabhupada explains.

Devotee – "Is the original body of the spirit soul a human form?"

Srila Prabhupada – "Yes, human form. God is also human form. "Man is made after the shape of God." I think there is in the Bible. Is it not? So God is also like human form. Here you see Krsna, two hands, two legs."

Hari-sauri – "How do we understand, then, that there are peacocks and flowers and trees in the spiritual world? Are these not eternal forms?"

Srila Prabhupada – "[describing material form first] Yes, they are more covered, just like if you cover your body with blanket, the hands and legs are invisible. But you are not the blanket. So the trees and plants, they are more covered. They are not in full manifestation. The human form is the full manifestation of the soul."

Hari-sauri - "Are they covered in the spiritual world?"

Srila Prabhupada - "Not in the spiritual world, there that is voluntary. Some devotee wants to serve Krsna as flower; they become flower there. If I want to be a flower I shall lie down at the lotus feet of Krsna and become flower, voluntarily, and can change from flower to human body if one desires. That is spiritual life. There is no restriction. If some devotee wants to serve Krsna as cow, he serves Krsna as cow, as calf, as flower, as plant, as water, as ground, field, or as father, as mother, as friend, as beloved, anything. It is inconceivable, yet a fact." (SB 6.1.1-4 - Melbourne, May 20, 1975)

As said above the word tatastha-sakti refers to the marginal living entities (jiva-souls) in their "fallen conditioned state" in both the material creation, and when dormant in the impersonal Brahmajyoti or Brahman effulgence..^*^..