Hi Aspirant

I don't think you have much time left  for GATE ,you have 1 month .It is impossible to do everything from scratch.What you can do is revise the topics which you have studied earlier and start giving mock test so that you will understand the question level and its type.After each test analyse your mistake and revise the topics in which you have done mistake and then after give test again.You can make formula chart for subjects to remember all imporatant topics with all formula.This can be helpful.

Good luck.