Hello,

If you wish to get a very good rank,you should definitely focus on test series. Previous year questions of GATE are not much in numbers and are solved by all serious students. One can easily complete it in short time if you have solved at least one time before.Your actual GATE performance will be quite similar to your test series performance.And dont bother much of test result initially,just stick to it,analyse your mistakes and continue giving tests.I know a friend who completed everything on time but did not gave much tests because of fear and now he regrets.

Hope this helps.....