Yes, Donation made on 10/06/2020 eligible for deduction u/s 80G in the AY 2020-21 because Goverment extended the date for making investment up to 31st July, 2020 for A.Y 2020-21
As per govt. notification, you can deduction of donation u/s 80G as well as other investment like :- LIC Premium, Medical premium, fd......etc.,in which invested upto 31st july 2020.