How much time do I have to find a new job if I am laid off on OPT with approved H1B visa.

If the company is not withdrawing the H-1B approved petition, your choices appear to be either applying for the STEM extension or finding another employer and having that employer sponsor you for another H-1B under the H-1B transfer route. It would be best if you would have the new H-1B paperwork into U.S.C.I.S. by October 1. I note that your status will automatically change to H-1B on October 1 if you do nothing at all. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.