outgoing calls not working

Can you please give me more information so that I can analyse the problem more clearly,like:

01. Please  tell me what error you are getting when you are trying make outbound calls? Can you please attach the screenshot of the error if possible?

02. For making outbound calls, the first call should come to your number and then to the customer. Are you
getting the first call?

03. Which operator you are using? Like. TATA or Reliance etc.?

04. Is it happening for some particular number or for all the numbers? If for some particular number, can you give me the number you tried to call?

05 For how long long you are facing this problem?