I live in a 3 BHK flat and I have the TP Link WR841, 5 mobiles, 2 PCs, 1 laptop. Works fine.
To be honest 3BHK is too vague a description to tell which router will be best suited.'
Router placement is important, a centrally located router will give good signal throughout. If the router is kept in one corner of the apartment, 'mine is, itd need more powerful antenaae though.
Total area, Room position, walls in between, even furniture placement, many factors are there.
WR841 is good for internet, I get full 4 mbps bandwidth even with one bar on my laptop, although file transfer from one machine to another gets really slow, like 2-3 MB/s. Even the max speed is 10 MB/s , i don't know how to utilise the full 300 mbps bandwidth, or even half of it.
Anyway, your choice to make.