Church has to give income tax or not .

Just being a religion based entity does mot automatically mean it's not required to pay any taxes. If that were the case, every second person will claim to be a Church of This or a Temple of That or an Agiary of the Other.

There are procedures to be followed to attain any exemption and also to continue to be eligible for any dispensation.

So yes, it is most certainly legal for the authorities to ask for taxes to be paid if the entity does not have valid exempt status.

Also remember, even any allowed exemption is not absolute and does not necessarily cover all activities and income of the entity.