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: 
Quintessentially I think that the problem is that you've got a cheap tripod. In order to have a smooth pan and tilt you need to get an expensive tripod head suitable for film and video work.

Because the cheaper heads work on friction you can make them move smoother using oils or other lubricants, however this will also prevent them from locking up completely meaning that you may get some drift at some point or even, if unlucky, render the head unusable until cleaned.

There isn't really a way around the problem as far as I know. Cheap heads are stiff and jerky while expensive heads aren't.
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.