"Narendra Modi can draw crowds but (we) will have to see if (he) can attract voters," said Wagh, who represents St. Andre constituency.
Wagh was allegedly attacked by the BJP cadre last year, apparently on reports that he was on his way out to join NCP.
"A crowd of such high number does not mean that all will vote for BJP for Lok Sabha elections," Wagh said.
Wagh had quit Congress to join BJP ahead of the state Assembly elections in 2012
According to organisers, around 1.3 lakh people attended the public meeting held on January 12 at Merces village near here.
Wagh, a writer-turned-politician, said he abstained from attending the rally due to presence of those people who had attacked him and felt threatened.
"People arrived to hear Modi and his views. He is a good speaker and people came to hear him," the MLA said.
Wagh, who had quit Congress to join BJP ahead of the state Assembly elections in 2012, was attacked by a mob on December 20 when he was returning after attending a public function in a village, 40 kms away from Panaji.
Wagh had clarified that he would remain with BJP and will float a social front for backward sections of society.