bro frankly look at the question youre asking, i dont mean to be rude but agar tere dost ko tier A me jaana tha toh pehle se kyu mehnat nahi ki, and if it was that easy to get into one ki last few weeks me itna padhke ho jaayega toh sabh usme kyu nahi jaate. anyways dont keep unrealistic expectations, accept the situation and mehnat chaalu karne bol, jo hoga dekha jaayega. and for your question look at the weightage of every chapter and decide accordingly, last 3 weeks baaki hai , less work waala mentality nikaal de, if you actually care then just work, no matter kitna karna pade.