AS you have asked about the tips for VITEEE,
VITEEE checks and choice students on the basis of concept, speed, accuracy, time management and decision building command. So very first thing is make a plan what to do and things not to do.

Follow a proper time table to check your level of preparation as per prescribed syllabus. You can check topic covered under VITEEE Syllabus.
You can follow the paper in below order (just a suggestion)
First: Chemistry
Second: Physics
Third: Maths

VITEEE paper has no negative marking therefore try to attempt as many as question but keeping the factor of time management in mind.
Sample papers are the best way to judge the level of preparation you have done. So, try to take help from previous year papers and sample papers for enhanced preparations.
Last and the most important thing is you need to be updated with the news regarding the entrance exam.
Now let’s discuss topic that need more concentration as compared to other topics.

Topics under Physics:
Electrostatics, Current Electricity, Effects of Electric Current, Electromagnetic Induction and semiconductor devices you need to concentrate more on these topics as most of the question will from these topics.

Topics under Chemistry:
Atomic Structure, Electrochemistry, Biomolecules, Organic Nitrogen Compounds, Alcohols and Ethers NCERT is the best source for In organic preparation thus you can refer to that.

Topics under Maths:
Vector Algebra, Analytical Geometry of Three Dimensions, Integral Calculus and its Applications are the tough topics thus give proper emphasis on them.