Hi Rishabh,
By using this function you can get the Last Sunday
This should work for all locales.
addDays([%BeginOfCurrentDay%],-parseInteger(formatDateTime([%BeginOfCurrentDay%],'u')))
Here we use the formatDateTime function with a format of 'u'. This returns the day of the week numerically, with 1 being Monday, through to 7 being Sunday. We then convert this to an integer using the parseInteger function, and subtract it from the current date to get previous Sunday.
https://docs.mendix.com/refguide/parse-and-format-date-function-calls/#1-introduction
I hope this helps.