Type "scp Desktop/index.html firstname.lastname@example.org:public_html/index.html" in ubuntu terminal. type yes if asked and enter your passowrd and it will show upload status.(Make sure you are on IISERK network; userproper address of your file on computer if it is in Download use Download/index.html. Also upload all other file/photo to server by refreing to thier file name for example ""scp Desktop/fb.jpg email@example.com:public_html/fb.jpg").
Whenever you upload something with same file name, it will replace the existing file on server.
If you are not comfortable with this command uploading, you can download "FileZilla" software for ubuntu where you can edit /delete /create file on your server directly and it will upload automatically when you save those file. WinSCP is similar software for windows. In such software use "webupload.iiserkol.ac.in" as host, "your user id" in user id, "your password" in password and 22 in port. After login to those software , you will see public_html folder, you need to save/create/upload all your file inside this folder.
Your webpage url is "http://students.iiserkol.ac.in/~userid/"