I have my H1b which is valid till Oct/2016. I might have to leave to India by Dec 2015, can I apply for H1b again if I want to come back after my current visa expires. Will it be cap exmpeted and if yes till what time I can apply?
You can get a new h1 filed by a US employer and such petition doesnt require to be in the H1 cap, if you have not used your H1 for full 6 years
Can I apply at any time? or there is any time frame
You can apply at any time.