H1B Grace Period

I was on H4 visa in US and filed for H1B visa in 2014. My H1B visa got approved in Oct’2014. No pay check has been generated till now as I am still looking out for a project. Employer says that after I have received SSN, I have 60 days grace period to get into a project and start pay check. Please let me know what this grace period rule is and if its valid in my scenario.