Earlier the anti rust coating was done by a small boy who works in the garage. I was not present at that time. This time I'll do the coating myself.
Few steps that I'll perform: (please add any steps that I have missed)
1. Wash the under body properly.
2. Let it dry and then inspect for any rust
3. Remove any rust using sand paper.
4. Wipe the surface with cloth to remove any dirt or rust particle
5. Apply a thin coat of anti rust primer.
6. Let it dry and then apply the second coat of anti rust primer.
7. Add a little thinner to rubber seal compound and apply a thin coat.
8. After drying the rubber seal coat, apply a thicker coat of rubber seal.
9. Finally let the coating dry and not drive the car for next two days.
I'll use thinner with rubber seal as if we apply thick coats of rubber seal it forms a hard layer and tends to come out.