Partition

First of all the legal heirs of your grandfather means their wife , sons , daughters have to file for legal heirness certificate in the tehsildars court of your area and after getting the certificate continue to further procedure to enter their name in the property as per their share .

If the grand father properties are ancestor or self earned, proper partition should have taken place. If no partition had taken place u have to go for partition suit first, In spite of that if the brother is holding share of his brothers also  it is illegal,  The son can file a suit for recovery of property and suit for mesne profits. for this the son should collect all the revenue records pertaining to that property.