There are lots of options for you but I would suggest you choose a single color for the wall with the TV, stairs and above. You need an area rug in the sitting area as well and you might get some color inspiration from your choice of rug. Good luck.

Very pretty. Very clean, open, simple, and elegant look. I like the 3rd photo the best -- I prefer the beige (off-white?) furniture over black. I don't think you need a rug -- but that's your personal preference. I agree with The Virtual Designer -- you have many good options -- I prefer light yet warm colors.
I also like hardwood maple floor :) --

Thanks ED

Thanks virtual designer. do you have any suggestions on ceiling (top) and I am worrying about illumination and loaction of light fittings so that it get perfect illumination. If I hang light fittings from top ceiling How do I maintain in case of lamp failure.
Other one is window location at first floor and size, For modern look as well as bring natural light inside living room.whether to have just above stair case or other loaction, shall we leave the wall as it is above the stair case with out window.

If your top ceiling is very high, then yea, it could be a problem with hanging lights and maintenance. How about a few floor lamps to help with illumination? I think if you can fit windows above the stair case and make it look nice, it would help a lot with natural light. :)

Thanks Ed, Again maintenance of window how do i reach window for cleaning but i accept it looks good window above stair case.

what's in your design??...nothing is in there,except rendered image....Design some thing behind tv as feature wall & do some corner treatment.