Tahseen Akhtar, said to be running Indian Mujahideen operations after the arrest of Yaseen Bhatkal, is also wanted by the NIA for involvement in other blasts.
Ten bombs exploded at Bodh Gaya's Mahabodhi temple in which two Buddhist monks were injured. Three live bombs were recovered and defused.
The Mahabodhi temple - a Unesco World Heritage site - is where the Buddha, born in neighbouring Nepal, attained enlightenment around 2,550 years ago.
At least seven people, including a suspected bomber, were killed and nearly 100 injured in the blasts ahead of the Oct 27 rally by the Bharatiya Janata Party's prime minister candidate Narendra Modi.
The NIA has arrested four people including Mohammed Imtiyaz Ansari in connection with serial blasts in Patna.