5. Aircraft intending to fly in formation
a. DGCA permission is to be obtained
b. appropriate ATS Unit is to be contacted for prior permission
avalanche ur answer was (b), in Rules of The Air, found the following
3.1.8 Formation flights
No civil aircraft shall be flown in formation.
well whatever u found is absolutely correct for civil aircraft but the question only mentions aircraft and not its type
and refer this source
SECTION 3
cheers