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: 
Force some talcum powder (or better yet, powdered graphite) into the friction surfaces of the head. This works like little ball bearings for the plastic-on-plastic rubbing of a cheap tripod head. Don't use oil, it just makes it worse.

I have a $25 Amazon Basics tripod, and this made a big improvement. I drilled a little hole in the panning head to force the talcum powder in, but maybe I could have just rubbed it into the cracks. It made a big improvement in the stiction and judder. The only downside is that it now smells like baby powder.
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.