As a general rule, the rule of presumption of legality of transactions is fixed in all civil codes of states. That is, all transactions that are not explicitly prohibited by the law and do not contradict the generally accepted rules of behavior in society are considered legitimate. That is, according to this rule, you can create altcoins, if the domestic legislation of India does not contain a direct ban on doing so. Therefore, you need to refer to the laws of your country.
I think that the creation of new cryptocurrencies is not illegal and, to be honest, real cryptocurrencies are not regulated in this case either. Therefore, this system is still new and no one has the right to accuse anyone of a crime.