Hi Girish
That will depend on your "own reporting tools" but in most cases you can get away with using the Client Credentials grant type. What's important to be aware of is the token duration time as your reporting tool may have to request a new token occasionally as part of it's querying process to the APIs.
I've set my customer's BI team up for using PowerBI and the client credential grant type has worked fine for them.
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Vaun McCarthy
NTT New Zealand Limited
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