The NATS system seems to work very well and accommodates aircraft of varying performance.. .Why not place a similar system over the area, say, between the western edge of the Kuala Lumpa FIR and the eastern edge of the Muscat FIR, (or the next radar controlled airspace for the more northerly routes). Dedicated east and westbound tracks would go a long way towards improving the current situation. . .. .Re-planning your route when airborne is not likely to meet with a lot of success in Indian airspace, IMHO.