>Does Nikon 50mm f/1.8G AF-S NIKKOR lens has to be used with >Tripod alwasy ?.
No! Long before VR was even a thought, 50mm lenses were being used handheld by everyone. Even by beginners since 50mm lenses were the the most common focal length for kit lens up until about 25 years ago.
>As it doesn't have VR feature, how it is >going to handle the handshakes during shooting.
Assuming that you are shooting a DX body, If you use a shutter speed of 1/80th sec. or faster with your 50mm lens you shouldn't have a problem with blur due to hand shake.
The Rule of Thumb is for a DX body is: Minimum Shutter Speed = 1/1.5 x focal length of the lens.
>Just wanted to know why prime lens doesn't have VR.
The 50mm f/1.8 has a 3 1/3rd stop advantage over the 18-55mm f/3.5-5.6 at 50mm. 3 stops will allow you to use a shutter speed 8 times faster than you could use with the 18-55mm with the same ISO. In other words if you were shooting at 1/60th sec. @ f/5.6 using the 18-55mm you could shoot at 1/640th sec. @ f/1.8. All of new (introduces since about 2005) primes 200mm and longer do have VR.