which book should i prefer for practising for viteee and what are some tips for the exam?

Basically, it is based on your 11th and 12th standard syllabus so better to focus on that and along with that practice on sample papers, previous year papers and once you get a good grip on your syllabus start doing mock papers. Mocks will be very helpful for your VITEEE preparation this will make you familiar with the exam pattern along with that this will be helpful for your time management as well. And I would also suggest you to use standard reference books only, you can consider below names like HC Verma, physics MCQ by D Mukherjee, RD Sharma, A Dasgupta MCQs (Mathematics), Advanced problems in organic chemistry by H Pandey.

Good Luck!!!