Change of status B1/B2 to H1

I have a valid B1/B2 visa and I am planning to go to US to visit my family. I will be staying in US till my i94 expires (6 months) and my employer from India is sponsoring me for H1. My question is, Can I stay in US on B1/B2 visa while my H1 is being processed? If picked in lottery and approved ,Can I change my status in US from B1/B2 to H1 without going for stamping outside USA?