"Once our army is allowed a free hand, the world will know how powerful it is," he said.
Rajnath Singh demanded "fool-proof security" to village heads in Jammu and Kashmir, many of whom have been killed by terrorists.
He also told the 5,000-strong rally that if the BJP won the Lok Sabha election, "we will start crop insurance for farmers".
The BJP candidate in Udhampur, Jitender Singh, is pitted against former chief minister Ghulam Nabi Azad of the Congress.
Udhampur will vote Thursday.
