EVDO is a 3G service developed by QUALCOMM. BSNL has taken another leap to introduce this 3G/EVDO - Wireless Broadband service in India. Its still in testing phase and very few areas have coverage.
Know More : http://www.bsnlevdo.com/
Here are some reviews from MouthShut:
1. Overall EVDO is not bad
Read: http://www.mouthshut.com/review/BSNL_EVDO-166183-1.html