Although one can go further back in history, let us begin with the Foreigners Act, 1946, whose preamble provides 'for the exercise by the Central Government of certain powers in respect of the entry of foreigners into India, their presence therein and their departure therefrom'. The Act effectively provides the Central Government with complete discretion in its dealings with all foreigners. This has largely been the basis of the legal framework for the treatment of foreigners in independent India - the only exception is that now foreigners in India are also entitled to certain fundamental rights that are not expressly restricted to citizens. For example, the Supreme Court famously ruled in National Human Rights Commission v. Arunachal Pradesh (1996) 1 SCC 742 that '... the State is bound to protect the life and liberty of every human being, be he a citizen or otherwise ……The State Government must act impartially and carry out its legal obligations to safeguard the life, health and well-being of Chakmas residing in the State without being inhibited by local politics.'
As such, Indian law does not clearly recognise a sub-category of 'refugees' within 'foreigners'. In many other countries, the treatment of foreigners is still largely a political decision, but the status of refugees has been judicialised by granting them rights. The Refugee Convention 1951 (read with its Protocol 1967) defines a refugee as someone who 'owing to wellfounded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion' is outside his/her country of nationality and cannot return. Although the fact has not been adjudicated upon by any court, it is fair to suggest that Taslima Nasreen was persecuted in Bangladesh for her political opinions that forced her to leave the country (it is not necessary to show that the persecution was done by the State itself). As such, she can avail the rights of a refugee outlined in the Convention in any of the member-states. One of the most basic of these rights is the right to non-refoulment in Article 33 of the Convention, that forbids the expulsion or return of a refugee to a State where his/her life or freedom will be endangered on account of her race, political opinion etc.
India, unfortunately, never signed the Convention and is not a member-state. India's refusal to join the Convention was a protest against its narrow understanding of a 'refugee' and its Euro-centric nature (which did not address the problem of the post-partition refugees that India was still dealing with in 1951). This does not mean that India has refused to accept refugees and provide them with protection. Thousands of Tibetan refugees and Bangladeshi refugees during the 1971 war were allowed to stay in the country. Even without having signed the Convention, India allows the UNHCR to decide upon the 'refugee' status for certain classes of applicants.
The main difference in India, it seems, is that the decision to accord any rights to refugees, or even allowing the UNHCR to function with a limited mandate in India, is a political rather than a legal one (just like any other foreigners). While this appears to be the practice of the Indian state, the Gujarat High Court did hold in Ktaer Abbas Habib Al Qutaifi v. Union of India (1999 Cri L J 919) that the the principle of non-refoulement is encompassed in Article 21 of the Constitution, so long as the presence of the refugee is not prejudicial to the law and order and security of
One wonders what the reaction of the Supreme Court will be in a case of violation of basic rights of refugees (say, if the hypothetical decision to expel a refugee like Taslima Nasreen is challenged because it violates the principle of non-refoulment). The patchy picture that emerges from the equally patchy description of law and practice above makes it difficult to hazard a guess. Of course, even if the Gujarat High Court judgment is endorsed by the Supreme Court, given the qualification of 'law and order' and how easily a 'law and order' problem can be manufactured in India, its utility in Taslima's case is doubtful. (If the Supreme Court has already ruled on this aspect, it has missed my attention - please enlighten.)
Perhaps, the best way forward, as the NHRC suggests, is that a comprehensive national law ought to be devised, keeping in view the decisions of the Supreme Court as well as international instruments on the subject. (Annual Report 2000-01, para 4.24 - available in the archives section of its website).
Till then, Taslima must rely on political generosity of the government of the day rather than legal rights.