I have divided the points in three different regions and then joined them, R1, R2 and R3 are the list of points for each of the three regions. Then I execute the code:
aux1 = ConvexHullMesh[R1]; aux2 = ConvexHullMesh[R2]; aux3 = ConvexHullMesh[R3]; R = RegionUnion[aux1, aux2, aux3];
And the result is:
So I have two problems: In the left region it is not taking into account the 'hole' and in the right side ones it is doing a convex region (as the command i used is convex). I have tried other commands but none of them work as expected. Any idea?