as per the rules of president house for visitor, not allowed late entry.

No... only govt ID card that too hard copy

My review stated that for me it was just a drive by look as it would have been a hassle for me to have made an on-line booking to see it otherwise and I had very limited time in Delhi. I'm sure if you google images of Rashtrapati Bhavan you might be able to get a better idea of it all.

No. Nothing was specified.

Luggage deposit is available. It does not matter which gate u enter. There is main entrance and u will directed to the entrance.

If it's for museum then you can spend 2 hr hour more as per interest,if it's for main building then nothing more than 1 hr,they have guided tour for 45 minutes,other than tour you are not allowed to explore anywhere alone .

Yes;You need to register 3 times and pay for each circuit separately.Also you will receive email confirmation for each of them separately.If you plan to visit all three circuits make sure you chose the timings carefully with enough transition time between each. The Rashrapati bhavan alone will take 2-3 hours and Museum circuit 1-2 hrs.

No.We are not allowed to take pictures inside the Building during the guided tour.Till reception you can take pictures.Camera can be brought and before the guided tour begins you will have to deposit it at the counter.

You should not carry any eatables with you. Security is very tight. There are many eatable places about three kilometers at Connaught Place, There are Govt canteen in North block and South Block, but they are closed on holidays and on week days you need permission to go into which you cannot do unless someone senoir working there can organize. Governor Amolak Rattan Kohli

The booking usually opens 60 days prior in advance. But you might need to reschedule your visit in January as India will be celebrating Republic day on 26th Jan'19 and due to security reasons the bookings might have been closed. But if you plan after 26th Jan'19 visiting the Rashtrapati Bhavan it would indeed be the best time as Beating Retreat ceremony is held on 29th Jan'19 which is open for tourists and is a must watch but tickets are limited and they follow strict timings of entry. If you are interested in visiting do keep an eye on their website from time to time.