Hi Aakash,
100 minutes is normal amount of time to complete AZ-104 exam that doesn't have labs:
https://learn.microsoft.com/en-us/credentials/support/exam-duration-exam-experience#exam-duration
Have you taken the free practice assessment? Do you have Azure Free account so that you can get more hands-on experience?
In addition to "normal" preparation, I recommend practicing searching documentation using Microsoft Learn search. Reason is, during exam you have access to Learn, however, you need to be able to find the relevant information quickly since you have limited amount of time.
Please click Accept Answer if the above was useful.
Thanks.
-TP