Aslamu alykum,I am Rizwan from India , my question is how to repent from kufr what are Arabic Duas and prayers for its repentance?

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.

Repentance from disbelief is by giving it up, resolving not to do it again, regretting having done it, and uttering the Shahaadatayn (The Two Testimonies of Faith).

If the disbelief was due to denying something that is known in the religion by necessity (by absolute evidence), then repentance from it is by acknowledging it.

You should perform as much as possible of acts of obedience and acts of worship that bring one closer to Allah, as good deeds wipe out the bad deeds.

You may also perform the prayer of repentance; you perform ablution, pray two Rak’ahs and ask for forgiveness for this prayer is one of the causes of forgiveness. You should also supplicate Allah frequently and remember Him much, and ask Him to make your heart firm on His Religion and make it subservient to His Obedience and protect you from polytheism whether it is apparent or hidden.

Allah Knows best.