What are the responsibilities of the person so summoned

A person who is issued summon is legally bound to attend either in person or by an authorized representative and he is bound to state the truth before the officer who has issued the summon upon any subject, which is the subject matter of examination and to produce such documents and other things as may be required.

(ICAI FAQ PUBLICATIONS 06-09-2017 Power to summon persons to give evidence and produce documents : FAQ NO. 20)