Dear Sindhu,  IGNOU is one of the top Universities and all its courses are widely accepted. And B.Ed from IGNOU in India is valid. B.Ed from India in other countries like US is also valid but it is indeed a long process to get your certification verified from the licensing authorities. A lot also depends upon state in the US, also level at which one plans to teach and apart from other requirements one would need to have TOEFl/IELTs scores too! Praxis test is most commonly used for teachers from other countries for getting licence in the USA for teaching.