There are some Aadhaar services which can be availed without a registered mobile number and some services need the registered mobile number. Aadhaar holders can also verify their registered email and mobile number.
Linking of Aadhaar is mandatory if an individual wants to enjoy the benefits of various government schemes and scholarships. However if you have already linked your Aadhaar with bank account then you can check the status of it online on the myAadhaar website. However do note only one bank account can be linked with Aadhaar.