Which book should I study for aligarh engineering exam

In order to crack+2 entrance examination you need to fully focus on syllabus prescribed by NCERT. I would suggest to follow NCERT books of Class IX and X ( Maths and Science) and then refer to some side books such as S.Chand and R.D Sharma. Make sure that you have made your concept clear from the NCERT books. You can also practice Question from Conceptum Guide that you can avail from any stationary shop in Aligarh.

Don't forget to study about basic Islam concepts and about Prophet Muhammad (PBUH). Approximately 10 question related to Islam and Prophet Muhammad ( PBUH ).

Current Affairs. Yeah. This is important. 56 question in General Knowledge part are based on recent events. Delhi Sultanate and Mughal Dynasty is another important part that covers 34 question in the examination.
Thank you :)