New Viewer...Neil's Backstory?

I used to watched Naamkaran when it first started but then stopped watching. So I know the whole story about Ayesha, Avni and why Dayanti wouldn't accept them and why Aman/Amol was accepted by the Mehtas.

However what I don't understand is what is Neil's relation to the Mehta's?

I just randomly started watching episodes from mid-May and will hopefully catch up soon but it's obviously well after the leap so the episodes don't explain Neil's backstory.

Thanks!

Simi