Hi Nitesh, it took you almost 2 years to post your first message since registering
As per my knowledge and understanding scjp certification is valid for 2 years so can I give the upgrade for 6?
The SCJP certificate is now valid for infinite time, it doesn't expire. I would recommend that you go for the upgrade exam 310-066 as you are already SCJP from previous version. SCJP 5 is too old now, so go for SCJP 6...
[Edit: Changed not to now]