Hi Balaram,
I think the TOP N should be left to the front end reporting and not restricted to the HANA information model. The TOP N records generally also depend on the selection criteria like date range, item codes (item categories) etc. Hence restricting this in the HANA information model may not be a good idea.
And secondly, why complicate things, when they can be simplified by a simple SELECT TOP ... statement. 
Regards,
Ravi