Currently am using Canon EOS 600D with 18-55 mm lens. I am concentrating on portrait photography . i need some suggestions for the lens that i can use for it.
You really can't go wrong with a 50mm f1.8, especially if you're just starting out.
For portrait you can look at lenses of focal length between 70 to 200mm. The depth of field produced at this focal length will help in separating your subject from background and also help in flattening the subject.
That being said, there are portrait shooter who get very amazing portrait from using wide angle lens. It all depend on the style or 'look' you are trying to achieve.
But 70 to 200mm is a good place to start.
hope it helps