Hello,

In the Bihar UGMAC allotment letter, "Compensation Seat against UR" means that you've been allotted a seat that was originally reserved for the Unreserved (UR) category, but is now being offered to you as a compensation. This typically happens when:

- You belong to a reserved category (like OBC, SC, or ST), but your rank is good enough to compete with Unreserved candidates.

- Some Unreserved seats remain vacant.

As a result, you're being given the opportunity to fill that vacant Unreserved seat. This compensation seat ensures that you get admission into your desired college/branch without affecting your category's original reservation benefits. It's essentially a bonus seat, and you'll still avail of the benefits of your original category.