Following points should be remembered before going to apply online for GDS vacancy.
1. Keep your mandatory documents are in Scanned format such as 10th Certificate, Photo and Signature. Community Certificate is mandatory for other than Un reserved category.
2. Documents scanned and resized based on requirement. (read notification)
3. Keep your mobile in hand for applying 2nd Step i.e Apply Online Option. In this option OTP will be send to your mobile within a minute or more based on the server response. (Sometime it will take 5-10 minutes. Don't click resend OTP again and again)
Below video shows the procedure to apply for GDS vacancy in India post