How to decide between %type and %rowtype in the following scenario:- I have 1 table with 60 columns and out of them, 40 are not used in stored procedure. Does %rowtype take a lot of memory in that case or is it better to use it?

I would probably go with table.column%type (anchored) for two reasons. One is that you are dealing with the minority and the other is for documenting the columns used in the procedure. With %rowtype, you will still have to know the columns if you are only using a subset of them for other DML.