No dear you cannot give CAT exam because you need to be at least a graduate to be eligible to give CAT exam.
Also just to add in to your information you need to get minimum 50% in your graduation (minimum percentage) to apply for CAT but remember to get admission in top colleges through CAT specially IIM's you need to get a percentile above 99.5 (top IIM's) and have good school academic records.

Carefully pay attention to your studies and marks in 12th, graduation and future goal.
You can even go through CAT details and eligibility criteria in detail below:

CAT eligibility

All the best!

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