Right to petition as in sending grievances and complaints to the government or a government body.
The only thing I found was article 350
Every person shall be entitled to submit a representation for the redress of any grievance to any officer or authority of the Union or a State in any of the languages used in the Union or in the State, as the case may be
but the section is titled "Language to be used in representations for redress of grievances"
The Indian Constitution doesn't contain an explicit "right to petition" clause. But there are other clauses that could be seen to imply this right.
Firstly, recall what the right to petition means. If you go back to the middle ages, or if you visit some autocratic states today, you don't have this right. Petitions are seen as complaints or criticism, and criticism of the government is likely to result in harassment, arrest, imprisonment or execution. The right to petition only means that the government should not punish you just for asking for change. It doesn't mean that the government has to do what you ask.
The Indian Constitution has, in clause 19 a "freedom to speak", and it may be argued that your freedom to speak to the government and not be punished for doing so is protected by this clause. That is, a petition is a form of protected speech. And, as you have noted, the freedom to petition for redress is implied in the section on languages, which says that as a practical matter, you can use any of the national languages in your petitions to the government.
See https://www.jstor.org/stable/43110886 and https://cic.gov.in/sites/default/files/2016/5S-1-Prof.%20Madabhushi%20Sridhar%20Acharyulu-%20ICEvaluation%20of%20Human%20Right%20to%20good%20governance.pptx
