Hello..
Group code would have been given to you when you've applied for your higher secondary education. For PCM with compuer science, the group codes is 104. For PCMB, the group code is 103. Check the official website for other group codes.
https://www.careers360.com/question-what-is-the-meaning-of-group-code-and-register-number-asking-in-tnea-form-for-outside-tamil-nadu-cbse-students
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