Hyd peeps! Please help me identify any issue with this rental deal.

I found a flat to rent in Whitefields area. In my experience of renting in various cities, including Hyderabad in the past, owners ask for 1 or 2 months of deposit and 1 month of advance rent. So if I move on 1st Jan, I pay 3X to the owner of which 2X is the deposit and 1X is the rent for Jan. However, this particular flat owner is asking me for 3 months deposit and no advance rent. So I still pay 3X on 1st Jan when I move to the flat, but all of that goes towards deposit. 1st Feb is when I pay the rent for the month of Jan. In monetary terms I think it is one and the same, but I am not able to wrap my head around this. Is there any downside of this arrangement for me? Also, while we are here, is it normal to give a 2 month notice for vacating the flat? When I was in Hyd few years ago , owners would ask for 1 month notice. So want to check if this is a new trend.