Numbers do not have a language per se so you must be storing this data in a text field - that is your problem. You should always use the correct data type - how it "looks" is a problem for the presentation layer to solve, not the database.
Other options include (potentially) using Collate in your query (this will badly affect performance though) - see
MySQL :: MySQL 8.0 Reference Manual :: 10.8.1 Using COLLATE in SQL Statements[
^]
You overcome the performance hit, you could add another column that holds the rollno "translated" (make sure this is the one referred to in the indexes)
This OP had a similar issue, there are some suggestions on how to get around it
convert-amount-from-english-to-other-language-in-sql-server[
^] - you could adapt the function for Bangla to Gujarati to get the extra column I mentioned.