Is Rewrite Content Ok for Google Ranking ?

There's no problem re-writing articles. I re-write articles everyday. I just take a few articles and then put them in my own words. Had no problems ranking articles that i've simply put into my own words.

Google may rank it if you can increase traffic...but matter is that how you can increase traffic if it is a rewritten content.

It's an all or nothing thing. When Google generates the SERPs it identifies any duplicate content, and if it finds any the one with the better overall metrics ranks while the other(s) don't show up at all. Rewriting by hand you shouldn't have a problem, but with any kind of automated method you're going to want a certain amount of uniqueness. By that same rule, you can actually straight up copy & paste content and outrank the original if you have stronger metrics. You have to consider the competition in terms of other metrics to decide if and how you're going to rewrite something and try to rank it.

Google always wants unique articles for building authority for that writing.Its good for writer but bad for SEO.