Can you please advise me if I can carry a power bank on flight/hand luggage, when traveling from Dubai to Goa on Oman Air?
Yes. You can't have them in checked luggage, but you can carry up to two in the carry-on luggage.
Source: Times of Oman:
“Carrying power banks in check-in baggage is not allowed in Oman Air. However, each passenger is allowed to carry two power banks in the carry-on bags (hand baggage),” a spokesperson of Oman Air said.