Which books should I refer to get the best results in AIBE? Which are the most important topics to focus?

If you don't get your chosen AIBE test city, the BCI gives you the next the nearest center that has space left. The details will show on your hall ticket, so check it carefully.

You have to go to the center that's given to you, since changing it later is mostly not allowed. The exam is

Students appearing for the AIBE exam must carry a coloured copy of the AIBE admit card. They must paste a recent coloured passport size photograph on the admit card. They must also carry a blue or black ball point pen to the exam centre. They must not carry any other stationery item to the AIBE test

You can't change your AIBE exam center after you send the form and get your center fixed. Once it's given, that choice stays final.

Centers are given as per what you picked, how many seats are left, and who applied first. It works kind of like first-come-first-serve, so you should choose ca

Following important details will be mentioned on the AIBE 21 hall ticket- 

Candidate's name
Hall ticket number
General Guidelines
Exam date and time
Exam centre details