which books should i refer for jee physics and maths?

and also for NSEP

Good to know abouit your concern for your future, great!...yes you may go ahead with Khanna and along with it you may follow NCERT books, join some coaching center with good reputation, download sample papers and previous year test papers for practice and eventually for better results. Additionally you must keep on surveying for a quality conscious college/university where you may live your dream of being an engineer. To my mind you may try at these places – B S Abdur Rahman University, Chennai,................Amrita School of Engineering, Bengaluru,................Lovely Professional University, Phagwara,................PEC, Chandigarh