custom duty on jewellery and camera

hi,

I am currently residing in UAE for past 8months I have bought jewellery and returning to India next month . will custom duty be levied as period of stay is less than one year ? value if less 1lac and < than 20gm.
if period of stay for one year is calculated should it be continuous stay of a year or occasional visit is also admissible in a year?
also is custom duty levied on used DSLR camera?