Please follow the guideline of signature pdf link. given on the same form while uploading

• Login in desktop or laptop
• Clear cache and history in your browser
• Ensure that your browser is up to date.

• Dimensions must be as follows 1.0 cm Width x 3.5 cm Height
• The maximum pixels  must be 160 x 560 Pixels and Minimum pixels  80 x 280
• The format must be JPEG/JPG
• Minimum aspect ratio is 0.30 and Maximum aspect ratio - 0.26
• File size must be in between 5 KB to 200 KB
• Signature must not be done in big alphabets
• Blue of black pen must be used for signature.
• The signature must occupy 70-80% of the box.

Hello there

There might be some problems with the size or aspect ratio of the picture you are uploading .checkout whether the size ratio and the aspect ratio are according to the mentioned one .If not then you can crop or edit the picture .You can also use the online tools for editing and resizing of the picture .These websites are free and you can very easily change the pic dimensions through these online tools .I personally use picresize .In some cases there is any problem with the website so you can wait for few hours before uploading the pic again