Hii,I will try to help you.

Thing should carry on exam:

Admit Card

Adhar Card/Driving License

Disability Certificate (if required)

A Clear Clipboard.

Pens and Pencil

Digital Watches

Things should not carry on exam

Calculators

Log Tables

Electronic watches

Printed materials

Paper

Docu Pen

HI there,
The most important thing that you must carry for your exam is self-confidence and patience.

Sometimes you know all the answers, but you get overconfident or less confident. which affects your performance. don’t be overwhelmed if you’ve less time to complete your exam. Keep writing until you’ve got one single minute. 
And the physical things that you must carry with you for your exams are:-

1. Hall ticket
2. Stationary items ( pens,pencil,eraser,scale,sharpener & extra refills)
3. Colour pencils if you are going for theory exams.
4. Exam pad if they permit
5. Id cards like Aadhar card or Driving license ( For Competitive and government service examinations)

NOTE:- Some Government Entrance exams like JEE and NEET don't allow you to carry your own pens and pencils, instead they provide you with one themselves so you should not carry yours there as it can be considered under use of unfair means.