Hello dear..

Firstly, if you are not crazy for a particular branch, please try to give priority to a good college instead of a good branch. A good college with average branch would give you a good placement/package, whereas a good branch in an average college won't.

Try to put options which have high cutoffs first, and then go further in descending order.

Secondly, try not to select colleges that are very far from your house, as daily travelling might become little hectic(you can if it's a very good college).

If you have a decent score, don't go on filling colleges just for being on safer side. This might end you up in a college that you did not prefer by choice(if that option falls in between by mistake).

Fill the form properly, as most students don't get a different college in 2nd and 3rd round and you have to be satisfied 

Best of luck..