12A registrations are the income tax exemption registration given by income tax department to NGOs. A Charitable NGO can apply for income tax exemptions certificate 12A, after getting the 12A registration the NGO's no need to make tax. After getting , the donor can claim income tax deduction from their individual taxation.
Now, after initial registration of 12 A, Department is approving the same for 3 years ie NGO will get a provisional registration certificate for three years and this can be renewed after 3 years. After renewal, the certificate will be valid for 5 years. All NGOs has to renew their certificate for 5 years.