The money will be taxable in the hands of the donee depending on what is the amount which is gifted to him
Section 56 of income tax act deals with what is the threshold for money above which it is taxable and also specified relatives between whom the gift transaction has taken place which has been exempted from payment of tax by the donee
If the money is essentially to be returned then it is nothing but a loan transaction and cannot be termed as gift
Loan agreement in such a case can be made which would require nominal stamp duty and attestation before public notary. Registration is not compulsory for loan agreement
Also in case of default in repayment of loan, the jurisdiction of the court will be to the court where the cause of action arose or where defendant resides
You also need to take certain security from your uncle which can be touched by you in case he defaults, by selling the same and realising and adjusting the sale proceeds against your loan with interest
The money can be remitted to your NRO account in India and you can issue a cheque to your uncle, of such account
In case of remittance out of India, I guess there is some restriction by RBI under the FEMA law