Representatives of the Sikh organisations held a meeting before the protest march started from Gurdwara Jyoti Swarup, and discussed the steps to be taken in this regard.
Over 75 lakh signatures have already been collected on a letter seeking clemency for Bhullar, representatives of various organisations said.
The letter along will be handed over to President Pranab Mukherjee on April 19, they said.
They appealed Punjab Chief Minister Parkash Singh Badal to convene a special session of state Assembly and pass a resolution favouring clemency for Bhullar.