[pharmacist2005]

I am not sure whether you are talking about visa approval notice or visa stamping. once you got your h1 approval you can go for stamping anytime but make sure its ok with your employer.

since you spoke about emabassy i am assuming that you have h1 b approval and your h1 b stamping interview may be delayed beyond october / 3 months. It is not necessary that you have to enter immediately but you should get your stamping done before your h1 b approval notice expires. once you reach US you'll get your I-94 with the date which will be the date of entry in US. In all this please consult your company's lawyer to ensure you have proper papers and your company is willing to wait till you get here. If you are coming to a state where SSN is required to get intern license then you need to get here to apply for SSN in person with your h1 paper and I-94. once you get ssn you can then apply for intern license and start working once everything is in place. The state board of pharmacy doesn't come into picture till you apply for intern license. some states have validity period on the intern license like 2yrs etc.... so you have enough time once you have intern license in hand.

if you can explain your situation better i am sure many of us can answer your questions properly.

I hope i haven't confused you. once again...your company's lawyer is the best person who can answere your doubts regarding visas.