The northern state will go to polls on December 7.
Mehta had won the seat, which has a sizeable number of Muslim voters, in the 2013 assembly elections with a margin of over 30,000 votes.
"I am fully confident of retaining my seat. I am not under any fear or pressure. My supporters and party workers are quite excited about the poll battle with Pilot," the 53-year-old BJP leader said.
Mehta, who filed his nomination papers on Thursday, said developmental works worth Rs 2,000 crore were executed in the last five years in the state.
"Illegal slaughterhouses were the main problem in the city and I got them shut. Number of district hospital beds were increased from 200 to 275. New grid substations were installed, while a water pipeline was laid in Tonk to address water issues," he said.
The BJP MLA said he was a "local" and Pilot was an "outsider" for Tonk.
The Congress, meanwhile, is eyeing the assembly seats in eastern parts of the state with Pilot's nomination. Pilot is also seen as the party's chief ministerial candidate.
Apart from Jaipur, Tonk district touches boundary with Ajmer (eight seats), Sawaimadhopur (four seats), Dausa
(five seats), Bhilwara (seven seats) and Bundi (three seats).
"Tonk is a good seat for me to contest which touches Ajmer and Dausa. Since I announced to contest the elections, there were requests from 13 to 14 districts and the party decided Tonk. We will win a significant number of seats in the entire Rajasthan and particularly in the eastern parts," Pilot, 41, said.
"The party workers have worked hard not only in this region, but in the entire state and the result of the election will make this clear. Not only Tonk, but the party is also going to win a majority of seats in Rajasthan," he said.
As many as nine candidates had contested from Tonk in the 2013 assembly elections where Mehta defeated his nearest rival Saud Saidi, a Congress rebel who had contested as an independent. The BJP leader had secured 46.96 per cent votes.
The constituency has about 2.22 lakh voters, including around 43,000 Muslims and 35,000 people belonging to the Scheduled Castes, apart from a significant number of Gurjar, Jat and Meena voters, according to estimates by candidates.