Are you trying to deploy Ev3 series VMs in Jio India West Region? If yes they are currently in high demand and you would need to create a new support request to get access after a delay. You could try with different size, for example, Ev4 series and see if that succeeds.
If you are not deploying to Jio India West but are seeing allocation or other errors I would suggest trying with a different (but similar) instance size such as Ev4 series and see if that is successful. Please review pricing so that you are aware how much the different size will cost.
Please click Accept Answer if the above was useful. Please add a comment below if you have questions or deploying with different VM size isn't working. Please post the precise error message(s) you receive when the deployment fails.