The Bharatiya Janata Party (BJP) has been trying to woo people for the upcoming assembly election in the state. However, security agencies have been facing serious challenges to provide complete security to the Prime Minister.
Over 2,000 police constables and 1,000 magistrates and police officers have been deployed especially on rally duty.
Meanwhile, Modi's scheduled visit to Bodh Gaya's Mahabodhi temple has been cancelled, said media reports.
Security officials were quoted as saying, "We have rehearsed the carcade movement today. 10 new gates have been made at Gandhi Maidan rally venue to deal with crowd. Earlier, there were just three gates."
"CCTV cameras have been mounted at vantage points. Metal detectors have been installed at the gates. Everything will be 100 per cent ready by today evening," officials added.
BJP President Amita Shah, former Bihar Chief Minister Jitanram Manjhi and many other BJP leaders are expected to accompany Modi to the rally.
Modi is expected to reach Gaya shortly after noon. This would be his second visit to Bihar ahead of the assembly election which is likely to be held by the end of 2015.