Since the exams are arriving .

You first need to cover up all the questions of ncert.

for the learning and understanding purpose for economics you should read from VK Ohri and TR Jain. 

For economics the best books are DK Goel , TS Grewal . Since you are left with february . You should now start doing 2 mocks everyday .

for business studies you should read from Sandeep Garg .

besides books you should be determined for exams :)

Wish you luck