PROCEDURE OF DISOWNING OF SON

Get a public notice published in 2 newspapers (one national  English and another local) and issue necessary legal notice to your son with copy of newspaper. 

Execute and register a "will" debarring him (with his family) from all your properties.

If you want to debar him (your son)from your self-acquired /share of ancestral immovable properties permanently, you should  file a declaratory suit in Civil Court thorough a local prudent lawyer. 

"Dispwning the son"! To my knowledge, this is a procedure unknown to Law.

Fight the Case.

Give your son his share and live separately.

But you have to mention that he's your son in relevant records.

As Shri P. Venu said, no divorce between father and son.