Question: Few months back I purchased a second hand tripod.  

Later on I noticed that the head *(which holds the camera)* of the tripod doesn't move freely.  

I mean I have to apply some pressure to make it move left and right, and even when it moves left/right it jumps some fixed *x* degrees, i.e I can't make it move *x+1* degree, it moves straightaway to *x+5* degrees.

I don't know whether this is normal or not, but this is very annoying.

Is there a way that ***I*** can fix it? Perhaps by oiling at some right spots?

Answer: 
There are usually screws which restrict motion in different directions, perhaps one of these is a wee bit too tight? Is the movement smooth or jerky? Try loosening the fixing screws a little bit at a time to see if that helps. 

What brand of tripod? One of the differences between good and bad (i.e. expensive and not-) tripods is ease and controlability (sp?) during adjustment. If it is a cheap tripod you may have discovered why.
My benro has a dial on the side that if I loosen it, it also loosens the ball inside the head.