Got my line profile changed to 4 Mbps. Getting speeds around 3.4 Mbps.
Process Followed : I am from Cochin, Kerala. Went to BSNL office, they mentioned will send mail to Bangalore office (?) since server setting there has to be changed. No change for 4 days. Called again, they gave me No. of Junior Engineer, called her, she said will do the needful, same day line profile changed to 4 Mbps.