What is the maximum accepted value for measured voltage between Ground and neutral ( 0 or 5 voltage or more)?

Neutral to ground voltages at branch receptacles are directly proportional to circuit length and circuit current and inversely proportional to conductor size or cross-sectional area ,earth system and balances between phases . In other words, making the circuit longer or increasing the circuit current will increase the neutral to ground voltage. Increasing the conductor gauge will reduce the neutral to ground voltage that occurs for any given length circuit at any given load

Depends upon the type of earthing system

It depends upon your circuit requirement  and type of earthing system.

I think it depends on the distance between the main transformer and the point you measure at.

it depends on the earthing system