refer any good ready reckoner or see Sec. 80G under incometax Act. For this visit incometaxindia.gov.in>Act>...

Deductions with and without any qualifying Limit are already mentioned and speified in the Act. Still for the Convenience i am Pasting the Write-up for your referrence. It can be easily deifferentiated in the 4 categories. Still if you are having difficulty, tell the donation type and to which authority, will try to help you.

Regards,

Donations with 100% deduction without any qualifying limit:

1. Prime Minister’s National Relief Fund
2. National Defence Fund
3. Prime Minister’s Armenia Earthquake Relief Fund
4. The Africa (Public Contribution - India) Fund
5. The National Foundation for Communal Harmony
6. Approved university or educational institution of national eminence
7. The Chief Minister’s Earthquake Relief Fund, Maharashtra
8. Donations made to Zila Saksharta Samitis.
9. The National Blood Transfusion Council or a State Blood Transfusion Council.
10. The Army Central Welfare Fund or the Indian Naval Benevolent Fund or The Air Force Central Welfare Fund.

Donations with 50% deduction without any qualifying limit.

1. Jawaharlal Nehru Memorial Fund
2. Prime Minister’s Drought Relief Fund
3. National Children’s Fund
4. Indira Gandhi Memorial Trust
5. The Rajiv Gandhi Foundation

Donations to the following are eligible for 100% deduction subject to 10% of adjusted gross total income

1. Donations to the Government or a local authority for the purpose of promoting family planning.
2. Sums paid by a company to Indian Olympic Association

Donations to the following are eligible for 50% deduction subject to 10% of adjusted gross total income

1. Donation to the Government or any local authority to be utilized by them for any charitable purposes other than the purpose of promoting family planning.

Although very important share by CA. Anupriya but It's better to refer to ready reckoner..

Now u got it...