80G is applicable for all

Yes. Donation Given to Baba Sahab Dr.Ambedkar Gramin Charitable Trust is eligible for tax benefit under Sec 80G of Income tax Act

Baba Sahab Dr.Ambedkar Gramin Charitable Trust is a registered trust under section 12A of Income Tax Act 1961.

The Proof of Donation depends on how you donated.
Example:-
Directly Deposited in Bank:Pay in Slip given by Bank(Customer Copy) which mentions Deposite Date, Amount, Cheque No(If any), Issuer bank name(If any), Branch Name.
Net Banking/online fund transfer : Extract of your bank statement or Print of Transaction.
Amount Given to our representative : Issued Provisional Receipt

Non-governmental organizations, or NGOs, were first called such in Article 71 in the Charter of the newly formed United Nations in 1945. While NGOs have no fixed or formal definition, they are generally defined as nonprofit entities independent of governmental influence (although they may receive government funding).