Yes, your Class 12th marks are important for NEET eligibility, though not directly for your NEET ranking (which is solely based on your NEET exam score). To be eligible to appear for the NEET-UG exam, candidates must typically satisfy certain criteria related to their Class 12th subjects and marks:

1. Subjects: You must have passed Physics, Chemistry, Biology/Biotechnology (PCB), and English as core subjects in Class 12.
2. Minimum Aggregate Marks in PCB: There is usually a minimum aggregate percentage required in Physics, Chemistry, and Biology/Biotechnology combined. For General category candidates, this has often been 50%, while for SC/ST/OBC-NCL candidates, it's typically been 40%, and for PwD candidates, it might be 45% (for General PwD).

These percentages are subject to change and must be verified from the official NEET Information Bulletin for the specific year. While your Class 12th marks determine your eligibility to sit for NEET, your admission into a medical college will depend on your NEET All India Rank and the subsequent counseling process.