Documents illegal

Which type of documents?  You complain to the concerned officers about the kind of fraud that was committed against your legal document/s.

Actually my dad given mother deed documents to her brother son he is not giving mother deed documents he is telling story I think some illegal forgery happened kindly tell us how to check and find illegal happened kindly let us know

You can seek mediation if possible, try to resolve the issue amicably through mediation. This can be less stressful and costly than going to court. 

If that person is intentionally not willing to return the documents then you can even lodge a criminal complaint against him for illegally retaining the property documents