Hi dhiraj,
It all depends on what the purpose of the certification will be. If you are going for a job change and want to do web programming (
jsp &
servlets) definitely go for the SCWCD. If you want to prove you are a good (or excellent) java developer then do the SCJD.
When you have taken SCJD you have to wait 4 to 6 weeks for your result, so in that period you can go for the SCWCD
Kind regards,
Roel