Replying to this thread with some context on the other one (Bose 650 system).
And the pics of the room puts some things in perspective.
Now if you have to work with your room to accommodate a larger TV, then the towers have to go to make way.
Retain the center if you like it; it shouldn't hamper viewing. Interesting that you have it vertical

Explore Bose sized cubes; there are other companies that make small speakers that sound.
And look great too. For movies you need the center and sub/s to punch.
That is really where the soundtrack energy is.
For all the other channels you may consider satellites that will hopefully solve the space and looks problems.
With sats, you can choose a modest AVR as the power requirements will not be high.
Since you are in Mumbai, you have the advantage of checking out more brands than us in other cities.
Do the legwork and new ideas/solutions will pop.
Cheers,
Raghu