You need to be more specific:

- Region?

- Clear-sky only or all-weather?

- Period?

- Temporal resolution?

- By "calculation", do you mean access to modeled data, measured data, or just your own model?

There is actually _considerable_ literature on this topic, usually called "solar resource". As a jump start, you should read

Technical Report Best Practices Handbook for the Collection and Use of Solar ...

https://www.springer.com/gp/book/9783319974835

Right Sir,

Region: if we have specific latitude and longitude of location and altitude.

We want to calculate all-weather or partial weather conditions and clear skies.

The time period between sunrise to sunset or any time of the day.

First I want to calculate by model data.

Thank you, sir, for your help.

Regards:

You did not define your region of interest...

There are many sources of data out there, but most are region specific.

Again, you need to read the documents I mentioned, then come back to us with more precise questions...