Your budget might not be sufficient for an integrated amp + bookshelf + subwoofer. Any decent subwoofer will cost at least 20k and decent integrated amps start from 25k. So your budget gets eaten up there itself. You can look for active speakers or used products to fit them in your budget.
Otherwise there's an FX audio amplifier on Hifimart.com for around 9k. You can combine that with a good pair of bookshelf speakers with a 5.5" or 6.5" low frequency driver. This will usually give you good bass. It might not be the same as a good subwoofer, but will be better than a cheap subwoofer (say something around 10-15k).
Among decent budget friendly integrated amps, you have Marantz PM5005 which is supposed to retail around 25k, but seems to be out of stock everywhere. You can check locally.
For speakers, you can look at Dali Spektor 1, Taga Harmony Platinum One, Elac Debut 5.2, Mission LX-2 MKII, Wharfedale Diamond 12.1, etc.
Try to find sellers locally and audition the speakers. Don't buy without listening. You'll not know what you like unless you've listened to something (assuming this is your first purchase of this nature).