Hello Madhusudan,
from your description it is not really clear what you are doing. My "little pronounced Sherlock Holmes genes" say me, that you are trying to implement a custom modification exit for an OData service using a stored procedure, right?
If it is so, you probably defined your interface wrong. The procedure interface of a custom modification exit expects an input table parameter with the type of the entity for which the modification exit is defined.
Regards,
Florian