Hi

No, you don't need to give CAT after 12th , moreover you cannot give CAT examination even if you want to give it with qualification of just 12th.

This is because,

Through CAT examination, admission in mba/pgdm is provided which is a postgraduate course, so to be eligible for CAT you must be at least a graduate in any discipline

For your reference

CAT eligibility criteria is given below:

To be eligible for CAT ,

• you need a Bachelor's/graduation degree in any discipline from a recognised university.

• you must have got  at least 50 per cent marks or equivalent CGPA in your graduation . SC/ST/PH students need only at least 45 percentage in Bachelor’s Degree in any discipline to be eligible .

• Candidates who are in the final year of their graduation are also eligible for CAT examination.

• There is no age restriction to be  eligible

• It is not mandatory to have work experience to be eligible

For detailed information go through

https://bschool.careers360.com/exams/cat

Thank you