Methods of registration?

For Registration The Vendor and The Purchaser both r sign in documents and attach a PAN Card copy, Property Photograph, Property related documents like - 7/12, B.U.Permission, Plan pass copy, N.A Order, Tax Bill etc... and pay a stamp duty and registration fee as per rate of Government.

In resale case the NOC of Builder it's necessary for your good purpose but for registration it's not necessory.

Thank you Bharat for your quick answer. If you can advice on my particular topic it will be great.

I have taken the possession of the flat since last 2 years. But the builder is asking for 1L more over and above the agreement, for grill modifications, to give the NOC. Hence I have not been able to register the flat.
Now I need to take a mortgage loan, but the bank won't give it unless the flat is registered in my name.

I have the sale deed and other documents, what should I do to register the flat?