I think you are asking - how to change your contact detail in careers360?

In that case, you should download the careers360 app available on playstore. Open the app and login using the email to your profile. When the app starts click on the three bar icon on the top left side. Click on the image icon. A interface will open having all the topics and answers and questions. Click on the three dot icon on top right side and from the pop up select "My Profile". There you will find the change mobile number option. Enter the new number and feed in the OTP given on that number. Your contact will get updated. You can change other details by clicking on the edit icon on that same interface at right corner below the menu bar. 

Hpe this helps.