Someone said that if you are outside US you cannot go to embassy now, because the H1-B visa is only valid for 3 months. If you visa is issued now, it will be expired before you actually enter US in Oct. Is it ture?
H1B Visa validity will be usually based on your H1B Petition and approval. USCIS can approve H1B petitions for any period of time (upto 3 years). Based on that US Embassy will issue H1B Visa and stamp in your passport. 3 More years of extension is available for a total of 6 years.
H1B Visa Validity just 3 months is incorrect. If your H1B Visa is issued before H1B start date as per your petition, which is usually October 1, if H1 is applied on April 1. You can get H1B stamping before that date, but you cannot enter US before your H-1B start date.