Calculate nested if in power query

You can edit the formula bar for the built in conditional column. First add a conditional column like this: 

Then edit the formula bar so it looks like this: 

Otherwise, click the button to create a new CUSTOM COLUMN in the Add Column tab, and paste this formula into the box: 

if [Required]= 0 then null else if [Country] = "India" then Value.Divide([Available] - [DowntimeHrs]/7.5 - [Required],[Required]) else Value.Divide([Available] - [DowntimeHrs]/6.5 - [Required],[Required])

Sriku  UPDATE: Don't forget to set data type to number when you're done too.