Can I perform salath in a mosque, which was build on a land taken forcefully from the owner.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It is impermissible to pray in a mosque built on a usurped land. If you perform the prayer therein, jurists hold different opinions regarding the validity of your prayer. Some are of the view that such prayer is invalid, and others held that it is valid, yet a person bears a sin for it.

Al-Mawsoo’ah Al-Fiqhiyyah (Fiqh Encyclopedia) reads: “Jurists held that it is prohibited to perform prayer in a usurped land because staying in such land is prohibited outside the prayer; therefore, it is prohibited to perform the prayer therein for a greater reason.

Scholars held two opinions regarding the validity of the prayer in a usurped place:

The majority of the jurists (Hanafi, Maliki, and Shafi’i scholars) held that such prayer is valid because the prohibition in this regard is not related to the performance of the prayer in and of itself, so there is no legal impediment to its validity … such prayer would be sufficient in terms of clearing one’s liability from the obligation of the prayer. He earns rewards for it yet bears a sin for performing in that place. He would be rewarded for his prayer yet bears a sin for performing it and staying in the usurped place.

The preponderant opinion held by the Hanbali scholars is that a prayer performed in a usurped place is invalid, even if it is jointly owned by two or more persons without division. This is because such prayer is an act of worship performed in a prohibited manner, and therefore it is declared invalid like the case with a prayer or fasting performed by a menstruating woman.” [End of quote, summarized]

Allah knows best.