GC filing for 5yrs IT experience but B.Tech in ECE

Sir,

Please guide what all options I have if my company is willing to sponsor my GC but I am B.Tech in Electronics and Communication from India and working in IT for more than 5 yrs(total exp India +US).

Also, do I need to get my experience letter from prev employers mentioning my Field of Experience( As I switched from various IT fields since I started). Is it required or a normal experience should fulfill the requirement.

Would there be any challenges in getting a GC?
Appreciate all your guidance on this.

Thanks much,