Hello student yes you're eligible if you full fill the eligibility criteria which says - Candidates must passed or appearing class 12 with minimum 45 percent marks aggregate from a recognized board. So even if you fail in 6th subject but passed overall then yes you're eligible.

For more updates refer to the link mentioned below - https://www.google.com/amp/s/law.careers360.com/articles/clat-eligibility-criteria/amp

Feel free to comment if you have any doubt

Good luck