The group allegedly belonged to Bangladesh-based Jamaat-e-Mujahideen Bangladesh, a banned terror outfit in the neighbouring country.
It will ask West Bengal government to hand over all the evidence collected by its CID department.
Union Home Minister Rajnath Singh made the decision following consistent demands from the state unit of the BJP.
BJP state president claimed that TMC did not want an NIA probe as its links with the terrorists would be exposed.
The NIA had proposed registering a case as a “preventive measure”.
The ISI organised training of IM operatives and also provided shelter to several accused persons.
Under the MLAT, either country can approach the other for collecting evidence against an accused.
NIA’s special prosecutor Subhash Bhattacharya told The Indian Express that the agency asked for time and the court granted it.
Tauqeer was also named by National Investigation Agency for organising terror camps in Wagamon in 2007.
Seven people were killed in the serial blasts in Patna at Gandhi Maidan, just hours ahead of Modi’s rally.
The NIA said Azmi was arrested after he arrived in India and cleared immigration, but made no mention of his alleged deportation.
Ahmad was brought to court under heavy security, with his face uncovered.
Centre and states cannot be adversaries in terror cases. A unified NCTC is crucial.
The arms haul led to the arrest of two persons, Thangdeihtung and Liankhanmanga, both aged 30 and residents of Champhai town.
The NIA also said their probe into these cases were “held up” due to want of interrogation of these accused.