The programme was organised by the RSS and hosted at Parliamentary Affairs Minister Venkaiah Naidu's residence at Aurangzeb Road.
A large number of BJP MPs, including women, and leaders of RSS and its affiliate organisations were present on the occasion.
After the flag-hoisting, Joshi delivered a talk to MPs where he dwelt on the contribution of RSS towards society and the social well-being and unity of the country.
RSS, he said, has struggled through turbulent and tough times and has been working towards nation building and character building of people in the country since 1925.
He also talked of the problems suffered by the Sangh during the Dravidian movement in Tamil Nadu and atrocities in Kerala.
The programme was also attended by BJP patriarch L K Advani and many Union Ministers including Sushma Swaraj.