Thanks a lot for valuable answers.
I came to US on 1st COT-2011 on H4, applied for F1 in Jan-12 for vocational courses and my F1 got approved for a year (till Jan-13). Intitally i got I-20 from school for only 6 months which is going expire on 31-AUG-2012. I also applied for H1b in 2013 quota.
If my H1b is approved, i will come under H1b status effective from 1st OCT. but my I-20 will expire on 30-AUG-2012, If i dont extend my I-20, will i be out of status for the month of SEP-2012?
Is there any provision for F1 people to live in country(1 or 2 months) soon after expire their I-20 (i mean if i dont extend the I-20)?