How to find proper breaker amp for surge arrester ?, is 65kA needs 63a breaker and 40kA needs 40a breaker ?, also it is good idea to use NH fuse instead MCB ?

 

The very best option will be to consult the manufacturer as to their recommendation for the protection circuit breaker. But if they are only producing copies of a product they will not know, and will not give correct information.

 

The very best option will be to consult the manufacturer as to their recommendation for the protection circuit breaker. But if they are only producing copies of a product they will not know, and will not give correct information.

Generally ? It is good than MCB ?

 

Generally ? It is good than MCB ?

A typical Miniature Circuit Breaker might not have adequate interrupting capacity because if it's small dimensions.
I am guessing that you are asking about the branch breaker installed upstream of the surge protector, and since the two capacities listed are 65,000 amps and 40,000 amps, both of those currents are probably greater than the interrupting capacity of a Miniature Circuit Breaker. THAT is one of the reasons that I do not use the little breakers in distribution circuits.
Usually the company that produces a device has an intended application that the device is intended to serve, and a specific set of conditions that will provide the intended performance.