I executed DBCC CHECKTABLE on one of my tables, and I got below error.
“table ‘tbl_students’ (ID 6589332541). Data row does not have a matching index row in the index ‘idx_tbl_students_id’ (ID 88). Possible missing or invalid keys for the index row matching.”

The above error is indicating the corruption of index “idx_tbl_students_id” so few records are missing.
If your index corrupted, there are two possible solutions. One is Restore your database backup and Second is Rebuild your corrupted indexes.

People are using REBUILD command for rebuilding the indexes, but in this article, I repaired the index using option REPAIR_REBUILD of DBCC.

You can use the REPAIR_REBUILD option with DBCC CHECKDB and DBCC CHECKTABLE. While executing those DBCC commands, you can repair corrupted indexes.

This can include quick repairs, such as repairing missing rows in non-clustered indexes, and more time-consuming repairs, such as rebuilding an index.

Following are example,

DBCC CHECKDB ('Database_Name', REPAIR_REBUILD)
DBCC CHECKTABLE ('Table_Name', REPAIR_REBUILD)

You can use below article and find script to rebuild all indexes of SQL Server Database:

SQL Server: T-SQL Script to Rebuild all Indexes of a Database