Default in notice u/s 133(6)

hello,

a notice u/s 133(6) has been recieved requiring assessee to furnish ledger in the books of assessee of third party and also ITR and B/S of relevant year of assessee.

* Is department correct in asking B/S and ITR of assessee

* The notice states to be replied within 3 days..but 40 days have passed.what are legal consequences that may be faced by assessee and how can be avoided?

*format of letter as a reply for the same

Regards