Hi! Deepan, 

Of course, you can get 150 marks in two months. For this you have to follow these steps :

Firstly, analyze previous year questions, focus on those chapters which have more weightage. Make a proper plan.  Ncert chemistry  is just like a bible learnt them. Additional chapters like polymer, biomolecules, environmental chemistry, semiconductor and communication, learnt them very well and revise properly. Solve more sample papers and previous year papers. Take a timed test series.After a long study, take a constructive break. Solve at least 30 questions of math per day in a given time. Focus on basic concepts and formulae which are very important. Revision is most important, revise properly. 

Good luck...