Did you create Robot type as Unattended or not ?
If not then Select Robot type as Unattended at the time of creating Robot in Robots page and then try once.
At the time of creating the bot there is also not any option for Unattended.
@ADITYA_MUKHERJEE Do you not get the highlighted Option below in the Screenshot :
this drop down was not coming, I had selected floating robot…then the drop down was not coming, then i tried with standard robot, now it shows the drop down with all the options.

