Commitment written on appraisal letter - because of personal reasons, I cannot keep my commitment

Hi All, I want to explain my case to you, so please bear with me for some time.
So I got retained in my company, but with that, my company demanded a 'verbal commitment' of 1 year to stay with them.
When I got my revised appraisal letter, my HR forced me to write "committed for a year" above my sign-on appraisal letter. As I was planning to stay with the company at least for a year, I have written so. But now, because of personal reasons, I cannot keep my commitment and am planning to move. But as I have given something in writing, I am afraid. Is it legit? Can they take any action against me if I am moving?

Such commitments are not valid in law and can be contested.
Subject is appraisal and seeking commitment is not in order.
Deal with case carefully.
Company cannot stop you from leaving but can delay release papers.