Please suggest what?
Any changes in number of days or city
"Any changes in number of days or city"
That's hard to tell because we have no idea what you want to do, or what you have organised. All you have told us is names of cities and days you will be there.
Now you need to research and tell us what you plan on doing in each area, and if your schedule will work for those number of days
Since this is the Bangkok forum - for hotels in Bangkok many tourists from India choose Pratunam and Siam areas. From India, men traveling with other Indian men in groups and singles often choose areas where more nightlife is available like Nana-Asoke and Patpong.
YOU choose where you need the hotel located. If you ask for a hotel suggestion YOU say where and how much you want to spend on a room each night. Use Thai baht. YOU choose what interests you.
Read the FAQ on the side for help. Know how to use meter taxis in Bangkok before showing up. Read up on how to convert your money to Thai baht. Read up on scams to avoid, etc.