Sathi ho,
Mero OPT June 30th,2009 ma sakincha ra maile Grad school join garne bichar ma chu. Ma school Fall 2009 ma join huna chahanchu ra tesko lagi k maile school ko I-20  on or before August 30th 2009 bhitra liye dekhi Fall 2009 ko class jahile suru bhaye ni ma status mai hunchu hoina?(kina ki 2 months grace period huncha OPT expire bhayesi) or maile I-20  June 3oth bhitrai linu parcha or summer mai class suru garnu parcha status bachauna ko lagi?
Please give me some advice?

You should be fine. You will be fine even if you can get the I-20 that starts from January  2010. Only tricky part is you will have to get your I-20 before your OPT expires.

If your new class starts with in 6 months from OPT expires then you don't have to leave the country.

Thanks

US