I believe development of Mini-Grid for remotely located rural areas will be better option as compared with extension of main grid. Mainly it is because when we extend the main grid it will stress the existing system. Main grid supplies the power generated from fossil fuel mainly in a country like India which will increase environment related issues.
The best option is to develop mini or micro grid using solar based generation which will provide power to rural areas without creating environmental problems.
Actually the extension of the Main Grid may not be economical to very remote areas and poor loads.
Also, the issue of weak transmission, step by step extension from Village to Village without the installation of Sub-stations and transformers may cause the poor quality of Power System.
The another factor is the defection and problems of the Main-grid.
So, In my opinion, the better Option is the Autonomous (Stand-alone) Mini-grid for Off-grid rural areas.