Pls Ditch Yamaha NS-8390 speakers. They do not have anything worth mentioning. They cost about 19K per pair. For that money, you can get wharfedale or Pioneer Bookshelves. You would get better audio quality of these two bookshelves.
https://www.hifimart.com/bonanza/wharfedale-diamond-220-bookshelf-speakers-pair.html
https://www.hifimart.com/speakers/bookshelf-monitor/pioneer-sp-bs22-lr-bookshelf-speakers-pair.html
Considering the low budget of speakers, I am assuming you are looking for budget amplifiers as well. Norge Amplifiers are great VFM budget stereo integrated amplifiers and go well with Wharfedale. Since you are in Kolkata, you can talk to FM
@shaan . He has a popular Amplifier board which are well appreciated in DIY circles. A simple DIY B1 Pre-amp & Shaan's power amplifier (while cumbersome!!) would give you amplification which would leap over all entry level branded integrated amplfiers.