how to get grand father's property

yes, you can claim the properties on your father's name, however, a concrete advise need revealing of more facts,

Your question is very less informative and the issue is very complex. You should have given the details of your age and the nature of the property you are talking about. You should really consult a lawyer at your place.

The moment your father and mother passed away (If they died intestate i.e. without writing any will) you are entitled to the share of properties of your father and mother. However, your share will depend on whether there are any other 1st class heirs along with you.

You can claim that share of property by filing a suit for partition.

Now coming to the property of your grandfather(Father's father) it depends on whether the property of your grandfather is an ancestral property or self-acquired. If it is ancestral you can claim. If it is self-acquired, you cannot.

Even if the paternal grandfather's property is self-acquired, if he expired without writing a will, the chances are there to claim your father's share.

First get a bonafide birth certificate.