Shastri had served as Chief Minister of Bihar thrice for short durations between 1968 and 1972.
Former Bihar Deputy Chief Minister Sushil Kumar Modi and BJP General Secretary Rajiv Pratap Rudy will attend the programme, Paswan, chairman of the organising committee, told reporters.
Leader of the opposition in Bihar Assembly Nand Kishore Yadav and others would also participate in the function on September 21, said the former union minister.
Earlier, Paswan had stated that BJP General Secretary Amit Shah was arriving here on September 21 to draw up the political strategy in the state, but later clarified that the plan has been dropped.