The case was filed by a BJP leader under sections 153 (A) promoting enmity between different groups,153 (B),171(G) and 504 of the Indian Penal Code.
A similar case was filed in Darbhanga district by BJP leader Arjun Sahni.
The chief judicial magistrate of Patna civil court has fixed May 19 as the date for hearing in the case, petitioner BJP leader Surajnandan Kushwaha said.
"The court deferred the hearing due to absence of defence lawyer,” he said.
Kushwaha said he had filed a case against Priyanka Gandhi for insulting and hurting the sentiments of the lower castes.
Priyanka Gandhi, the daughter of Congress chief Sonia Gandhi, on Monday said Modi had insulted her "martyred" father Rajiv Gandhi, and that the Congress booth workers in Amethi would give a befitting reply to his "low-level politics".
"They have insulted my martyred father on the soil of Amethi. People of Amethi will never forgive them for this wrong act. My workers at booths will reply to this despicable politics. Each and every booth of Amethi will give a reply," Priyanka Gandhi had said.
In his speech in Amethi on Monday, Modi had attacked the Gandhis and accused the Congress of "arrogance".
He said Rajiv Gandhi, when he was a Congress office-bearer, had "humiliated" the then Andhra Pradesh Chief Minister T Anjaiah at an airport.
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