I think NCERT itself is a sufficient resource for Chemistry for competitive exams. If you want to explore other books, then RC Mukerjee, O.P Tandon are good ones to start with.

After, Completing NCERT books you can refer below books to prepare for engineering exams Physical Chemistry O.P Tandon P.Bahadur R.C. Mukharjee Organic Chemistry O.P. Tandon Paula Bruice Yurkanis MORRISON & BOYD Arihant M. S. Chauhan Inorganic Chemistry O.P. Tandon J.D Lee All the Best!!