The prime minister showed a victory sign after he arrived in Parliament to attend the winter session. The parliament re-convened on Monday after the weekend break.
"Will form Government in both Himachal and Gujarat with clear majority" said Rajnath.
Earlier on Monday, BJP leader Shahnawaz Hussain said that he was confident that the party will secure a massive win in both the states.
"There is no doubt that the people in both Gujarat and Himachal Pradesh have blessed PM Narendra Modi and the BJP. The entire nation was eagerly waiting for these elections," he said.
He said that the BJP was heading towards victory.
"Today we are heading towards a massive victory thanks to the work our government has done in Gujarat for 22 years, the trust people have on PM Modi and the hard work of Amit Shah and party workers," he added.
The early trends on Monday showed BJP marching towards a victory in Gujarat and was set to retain power and also stayed on course to oust the Congress in Himachal Pradesh.
Main rivals BJP and Congress contested all the 68 seats at stake. The hill state witnessed a record 75.28 per cent turnout.
The Congress and the BJP had 36 and 26 seats respectively in the outgoing House.
(With inputs from agencies)