converting from H4 to H1B having never travelled on H1B

My H1B petition was approved in 2012 . However i never travelled , neither got it stamped, the approval was for 3 years( expiring october 2015)

Now i am in the US on a H4 visa and plan to join another company in another 4 or 5 months would i be considered in cap exemption still or is there a time frame within which i have look for a job and apply for H1

Usually you are cap subject once for six years. You should be fine.