L1B to L1A to GC

[Kochite]

Hi,

I worked for a company’s india subsidiary in a junior Project manager capacity having direct reports (professionals) , managing a org function out of India & used to perform appraisals. However when I entered US, I was on L1B since I came to US to work in a specialized knowledge capacity. While at L1B I continued to have direct reports in India. 6 months later I was promoted to project manager and started performing managerial role in US. While visa ext, I converted my L1B to L1A due to my changed role in the org. Will I be able to apply GC in EB1? If my employer doesn’t agree with EB1, I have to go with EB2. Currently I have stayed for 3 years on L1B (Start date is Dec 2014) and L1A is valid till dec 2019. How long I can stay and before when I should file for H1B for continued stay in US?