• Maybe dimension of your uploaded signature is more than the requirement.
• Maybe it's not clear
• Maybe internet speed is slow.You can try after sometime.

• If your uploaded signature would have any error then you will receive a message regarding this.
• You can contact wbjee through email or telephone numbers for detailed information.

Dear Acharya

These are the two options you have:

• In case it comes to the notice of the Board that the photograph or the signature uploaded by a candidate is not as per the specified requirement, a SMS is sent to candidate’s registered mobile number. Then he has to re-upload corrected photo/signature. This revised image is then approved by the Board, which needs about 3 days of time. If a candidate logs in during these 3 days, he will see an alert message as “Admin approval required”  
• or else you need to contact the wbjee team by using below contact details

AQ-13/1, Sector-V, Salt Lake City, Kolkata-700 091.