2.5 year old post...and you still haven't found a floor? Local species are always best for local climates. India has different wood species than N. America...so our suggestions are going to be of little help to someone on the Indian Subcontinent. Local hardwood works best in local climates. Work with that theory and choose the wood you like the look of.

OSB board will do the trick. You need another photo for us to offer a species and finish. Natural finish (clear coat...water based polyurethane finish...NO oil modified) in a low gloss or satin finish on white oak with FLOOD LIGHTS will offer the same "look" as the poor photo. Beyond that, you will need a better photo.

The wall is stunning and creative, but sadly, I have to agree with the consensus expressed on all your threads: this wood should have been bone dry, carefully checked over piece by piece for holes, insects, existing fungus etc., and probably treated and certainly well sealed before before being installed. At this point, I would cut my losses and take it down. Once the pieces are all down, it's possible that if you thoroughly scrub off all fungus with a bleach solution, then let them dry bone dry (preferably in a wood kiln or perhaps a DIY drying shed), then treat and coat, these pieces could be reinstalled. Even that depends on the conditions they'll see - if this wall is exposed to lots of steam or grease you'll be having new issues before long. Also, is the wall itself dry and solid? Any chance water is leaking or oozing from somewhere and adding to the issue? What species of wood is this? Some species are naturally more fungus resistant and appropriate for this than others. Long story short, I'd recommend finding a different way to cover the wall - with ceramic, galvanized metal, or with a really scrub-resistant paint.

I have been using BWR (boiling water resistant) Greenply Gold (19, 12 and 6 mm thick depending on end use) over the last couple of years. But there are others good brands too which are slightly cheaper. _ Raajply, Century, and more economical grades of Greenply. I find blockboard easier to work with than plywood, because there is less chance of bending