The occasion was - Luitporiya Hindu Samavesh (conclave of Hindu people of the Brahmaputra valley) - where over 40 thousand RSS workers had gathered for the mega rally along with thousands of BJP supporters.
The rally holds significance as the three states in the region - Tripura, Nagaland and Meghalaya - will vote next month.
The BJP came to power in Assam in 2016 on the plank of protecting the identity, land and culture of the indigenous people of the state.
"Respect all diversity. This is how humanity in this lifetime can be accomplished. This is an unique gift from our motherland," Mohan Bhagwat told cheering supporters.
"The idea is to make RSS more acceptable in Northeast. This is to give an image makeover. Since Northeast is diverse, there are lot of indigenous sect... there is wrong publicity about us, we want to change that," said Shankar Das, RSS spokesperson in Assam.
The northeast seemed well choreographed, more so at a time when the BJP's move to amend the citizenship act and give citizenship to Hindus from neighbouring countries has not gone down well with the indigenous communities in Northeast, since they are apprehensive about the huge influx of Hindus from Bangladesh.
"RSS has named the rally as Hindu samavesh, why is it only Hindus and why not all religions since this is a secular country. RSS is doing this with political motivation and to polarise people," said Ripun Bora, MP and Congress chief of Assam.