He has repented but he cannot restore people’s rights because he is poor

The basic principle with regard to people’s rights among
themselves is that it is based on setting things straight with them. It is
not waived just because one repents, rather rights must be restored to
people or the person must ask them to let him off. If a person repents
sincerely to Allaah from having transgressed people’s rights and he is
unable to restore them to them because he is too poor or because he does not
know who or where they are, then Allaah will accept his repentance and make
them let him off on the Day of Resurrection by compensating them with
whatever He wills. But if he is able to restore their rights to them in this
world or ask for their pardon, then he must do that, and his repentance is
not complete otherwise, because Allaah says (interpretation of the meaning):

“And all of you beg Allaah to forgive you all, O
believers, that you may be successful”

[al-Noor 24:31]

“So keep your duty to Allaah and fear Him as much as you
can”

[al-Taghaabun 64:16]. 

And Allaah is the Source of strength; may Allaah send
blessings and peace upon our Prophet Muhammad and his family and companions.
End quote. 

Standing Committee for Academic Research and Issuing Fatwas