Totally depends on what you plan to do in Bangkok.
If you are a backpacker and planning to stay in one of the hostels near Khao San Road, you will need INR 500/day for a bed and daily breakfast. A hotel room near Chao Phraya river will cost you around INR 2500 - 5000/day with breakfast.
A meal in a good restaurant in Bangkok can range from INR 1000 - 1500. Mc Donald's is a good option for cheap eats.
If you go to a club, the average cost for a Chang is INR 200 and INR 150 in a bar/pub.
Cost of Uber is pretty similar to that in India. Tuk tuks can get a bit expensive while Bangkok metro and city buses are the cheapest and very convenient.
Shopping in any malls would be stupid as most of the brands are available in India while shopping at Chatuchak Market is very cheap.
Other activities with cost:
Chao Phraya River Cruise with Dinner: INR 3000
Grand Palace entry: INR 1000
Sea Life: INR 1000
P.S. If you need more on Thailand check out the blogs below:
https://www.gonimad.com/blog/adventures-of-a-solo-indian-traveler-1https://www.gonimad.com/blog/adventures-of-a-solo-indian-traveler-thailand-2
Hello Nikita, a very happy new year to you. This is a very subjective question and for obtaining an accurate and a helpful reply to this, you need to tell me a little more about the kind of trip u want for these three days.Once that is clear, we can v well budget the trip for you.
Take care.
Happy Travelling
I suppose you should take somewhere around INR 20-25 k, as travel, stay and food is costly in Bangkok owing to the places scrambled all over the city. To be on a safer side, try carrying INR 5k extra, because fetching out cash in a different country incur heavy charges i.e. 3-4% of the transaction amount.
Keep travelling!!