GST REGISTRATION in lease agreement

you have to give the proof of place of business not any lease hold land so of it's your place of business you can proceed

Yes lease deed would be sufficient.

However, please note after submitting your application department might respond to that within 3days requesting for more details and they might ask electricity bill.

There are many instances where many jurisdiction officer do not raise any query but few officer does that.

As per rule 9(3), they have power to raise clarification or raise notice for documentation and it is at their discretion to provide approval.

So better have EB bill/municipal khata account/property tax bill ready.