I assume then that the tiles were laid in a grid pattern on the wall. You are probably cornered into a modernist design now:You can either keep it very minimalist and add art work as below to make a feature of the grid... you could add wood panelling over the grout lines to create an interesting wood panel feature.

Thanks for ypur suggestions. I have attached the pic of my living room. Can this grid be corrected with some polish on it?

I didn't realize it was a faux stone pattern. There is nothing you can do to hide the grid pattern I am afraid...However, as it is recessed in a niche, I am inspired by your windchime pattern to think of adding eyelet hooks on the top and bottom that align with the vertical grids and uplight them from behind...This idea but with less vertical rods, and then uplit to give an effect like the second picture...

I agree, place a skinny vertical sculpture of some type in front, so the rocks aren't the focal point.

Thank you. I want to paint the walls now. So I was thinking to do Ochre texture paint around the faux stone wall and keep the other walls simple sugercane color. Will it look good? Suggestions are welcome. :)