Is this true that if someone's income is haram,his repentance of other sins is not accepted? It is because as a part of repentance, that person needs to seek Allah's forgiveness for committing the particular sin he is repenting from and seeking forgiveness is a dua and dua made by a person is not accepted if his income is haram. Is this concept true?

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.

Forgiveness is undoubtedly of cardinal importance in Islam, and thus should accompany repentance to Allah. However, making forgiveness with the tongue is not of the conditions of repentance. As for the conditions of repenting from sins not relating to the rights of people, they are three: - giving up sins, showing remorse for it, and showing determination not to do it again. Whoever realizes these three conditions, Allah would accept his repentance, even if he does not make forgiveness with his tongue. Or that he sought forgiveness for consuming what is unlawful because forgiveness is not one of the conditions of repentance, since it (i.e. forgiveness) is some sort of supplications. A man may show repentance without supplicating, exactly as he may supplicate and ask for forgiveness without making repentance; that is to say that there is no connection between the two matters.

Allah knows best.