Actually the government has made it quite clear this year that unless a person is absolutely irreplaceable or involved in a critical project at the time of retirement, extension WILL NOT BE GIVEN. Under exceptional circumstances, some kind of contract in role of advisor can be given limited to a period of 2 years max. even with extension, the time period will be limited to completion of project or finding an alternate, whichever is earlier.
My views are that this is quite a welcome move, as most chief's were busy getting extension of their term after the age of 60 (retirement) and it effectively meant that little time was devoted to their own work. It also led to stagnation at lower levels leading to discontentment.