TL;DR
Articles 25 to 28 give you the right to freedom of religion. You have the right to practise, profess, and propagate your religion. The State cannot force a religion on you. Religious institutions can manage their own affairs, subject to law and public order.
Article 25 — Freedom of conscience and religion
Every person has the right to freely profess, practise, and propagate religion. This is subject to public order, health, morality, and other fundamental rights. So you can practise your religion, but not in a way that harms others or breaks the law. The State can make laws to regulate or restrict religious practice when needed for public order or social welfare.
Article 26 — Right of religious groups
Religious groups have the right to manage their own affairs. They can own property and run institutions for religious and charitable purposes. This is subject to law, public order, and morality.
Article 27 — No tax for religion
No one can be forced to pay a tax the proceeds of which go only to a particular religion. So the State cannot use your tax money to promote one religion.
Article 28 — No religious instruction in certain schools
No religious instruction can be given in schools that are fully run by State funds. In other schools, you cannot be forced to take part in religious instruction or worship if you do not want to.
In daily life
You can practise your religion, go to your place of worship, and follow your beliefs. The State cannot favour one religion over another. If you feel your religious freedom is being violated, you can approach the courts under Article 32 or through other legal channels.
Source: Constitution of India, Part III. Related: Right to Equality (Articles 14–18), Right to Constitutional Remedies (Article 32), Constitution and Freedom of Speech.