You won't find anything with the specs you want for your budget unless you buy a used system. Gaming laptops that can run new demanding games start at about $1,000 (50k rupee is under $800) for lower settings, to play at Medium at smooth speeds, $1,200 or so.
Nothing wrong with getting a year or two used gaming system though, just make sure you test it first. Anything with a NVidia 860m class video card is good for games, I would not go under an 850 if you want to make sure you can play games at smooth frame rates.