The project is under cancellation. How to claim the paid money back?

Dear sir/madam,

My father (an Indian resident) bought a property from a developer in 2018 via resale from a Dubai resident. The project has been under construction all these years but now is showing under cancellation on the Dubai Rest app.

All payments have been made from our side. What legal recourse can we take? And who do we approach in such a condition?