Rupani, who is a former Rajya Sabha MP filed his nomination paper, accompanied by Gujarat BJP President R C Faldu and ministers Nitin Patel, Govind Patel and Babubhai Bokhiria, alongwith a large number of BJP workers.
In his nomination papers, Rupani declared having assets worth more than Rs 7.5 crore.
The Rajkot (west) seat fell vacant after Vajubhai Vala who had retained the seat since 1990 resigned after being appointed as the Governor of Karnataka.
Meanshile, Congress candidate Jayanti Kalariya is expected to file his nomination papers tomorrow.