Tier 2 dependancy visa (for newborn child born in India)

Me (Tier 2) holder and my my wife(dependent) already have valid uk visas before our child was born.
Post which I have come on short term project assignment and staying on temporary shared accommodation. It is likely that couple of months later the current assignment would be converted into longer term.
I want to initiate my daughter's visa meanwhile.
Can anyone help me in listing what all documents are required,Is the rental agreement is must?
While entering in UK I have put duration of stay as 60 days and as well my deputation letter also says so. In this case it is likely that I would go back to India and get my family along and then look for rented apartment.
From the finance point of view I would be getting company's cover letter, maintenance funds letter and I would add my bank statements, salary slips,etc which will show that I can sponser my both dependents.
So is rental agreement is still required? VFS site doesnt mention it in document list.