GK & current affairs are the vast areas so there can not be any fix timing for the current affairs & GK section. Along with your 12th study you should develop a habit of reading newspapers daily from now on.

Current Affairs :There are certain business/economics related questions.Sports is another area where you can get the questionslike RIO Olympics, Paralympics and international achievements of Indian sports.

Static GK : There are the subjects like History,Geography,Science brush up all these subjects you have read pre 10th.
History : focus more on pre independence and post independence history of India.
Science: Focus more on day to day general science questions. Inventors,discoveries and past nobel prize winners very important.

Note: Try to give the time for GK & current affairs section as per your convenience.

Good Luck!

Good Luck!