He cannot retain Indian passport once he has taken Canadian citizenship 

he cannot travel on Indian passport 

he has to surrender Indian passport as he is Canadian citizen now 

Your son has acquired Canadian Citizenship.

The Constitution of India does not allow holding Indian citizenship and citizenship of a foreign country simultaneously.

some countries may require individuals to enter and exit the country on their passport of citizenship, which may limit their ability to use their other passport.

It should be noted that it is illegal to continue to use an Indian passport after the renunciation of Indian citizenship and defaulters will be faced with penalties.

• India does not allow dual citizenship with any other country, as per the Indian Citizenship Act of 1955. It is considered a punishable offence to apply for, continue to hold or obtain an Indian passport after acquiring foreign citizenship. Indian nationals who obtain Canadian citizenship are required to renounce their Indian citizenship and surrender their Indian passport within three months of acquiring foreign citizenship.
• If your son flies and enters India on his Indian passport without surrendering it, he may face legal or other issues, such as:

• He may be detained or questioned by the immigration authorities at the airport for travelling on an invalid passport and concealing his Canadian citizenship.
• He may be fined or penalized for not surrendering his Indian passport within the stipulated time and violating the Indian Passport Act of 1967 and the Foreigners Act of 1946.
• He may lose his Overseas Citizen of India (OCI) status or eligibility, which grants certain benefits and privileges to former Indian citizens who have acquired foreign citizenship.
• He may face difficulties in obtaining an exit permit or a visa to return to Canada, as he will not be able to produce his Canadian passport or proof of citizenship at the Indian authorities.

• Based on this information, it seems that your son should not fly and enter India on his Indian passport and then surrender it later. He should follow the proper procedure and surrender his Indian passport at the nearest Indian consulate or embassy in Canada before travelling to India. He should also apply for an OCI card or a visa to enter India as a Canadian citizen.

His Indian citizenship has been revoked,  so in one manner, Indian passport has become void automatically. Don`t use it. Come India on CAN PP and surrender I PP.

That will amount of commission of offence under Passport Act, 1967 punishable with imprisonment for a term which shall not be less than one year but may extend to five years and with fine which shall not be less than ten thousand rupees but which may extend to fifty thousand rupees or with both.

- As per the Passports Act 1967, it is mandatory for all Indian passport holders to surrender their passports to the nearest Indian Mission/Post immediately after acquisition of foreign nationality.

- Further, misuse of Indian passports constitutes an offence under Section 12(1A) of the Passports Act 1967.

- Hence, after getting the Canadian passport , he is under obligation to surrender the India Passport , it means that he cannot travel on Indian Passport .

If the foreign citizenship was acquired only recently then he can travel on the Indian passport within three months.

A grace period of three months is allowed from the date of acquisition of foreign citizenship, for the purpose of travel on an Indian Passport. Therefore, no penalty will be leviable for travel on an Indian passport within three months of acquisition of a foreign passport.

As per section 12(1) of the Passports Act, 1967, it is mandatory for all Indian passport holders to surrender their Indian passport to the nearest Indian mission / post immediately after the acquisition of the foreign nationality.

Misuse of Indian passport constitutes an offence under the above referred provision of law. 

Once he takes Canadian citizenship then immediately his Indian citizen is revoked. He can travel only if the said fact is not known to Indian authorities 

grace period of three months only is allowed from the date of acquisition of foreign citizenship, for the purpose of travel on Indian passport and hence no penalty will be levied for travel on Indian passport within three months of acquisition of foreign passport.

- Under the Indian Passport Act, 1967, holding Indian passport/acquiring Indian passport/travelling on Indian passport after acquisition of foreign citizenship constitutes an offence , and attracts penalties.

- Further, the grace period of three months will be run from the date of acquiring foreign nationality i.e. the date of Naturalisation certificate.

- Further, the date on the Naturalisation Certificate will be treated as date of acquiring foreign nationality and hence, it is mandatory for the applicants to produce his / her Naturalisation Certificate for obtaining Surrender Certificate/Declaration of Renunciation of Citizenship of India. 

This is correct.

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