Document verification for buying an apartment

Hi All,

 I am planning to buy an apartment in Bangalore. So I am looking for document verification by Advocate.

Please provide below details.

1) What all documents are required for document verification ?

2) From booking an apartment till occupying the house what all occasions we need legal consultation from an advocate? ( I could find -> Initial document verification, Sale Agreement, Sale Deed. If there is anything else please inform).

3) What would be the approximate charges for providing assistance with Document verification, Sale Agreement and Sale Deed ?

4) Is it good to get the advice from an advocate in writing during document verification ?

If so how much importance does it have?

Please provide details.

Thanks,

GD