Trending @Wipro; After how many days of getting mail of performance next is complete ,we get the hike letter?

No man it doesn't work like that. Your appraisal doesn't guarantee a hike. Your rating will not guarantee a hike. Whatever rating you get, you will be eligible for hike if your manager and HR agrees that you deserve a hike. Last year we got Maybe Salary Increase (MSI) on December this year we are not sure what is the situation. Most probably we will get MSI letters next year but still not all of us will be eligible for MSI yet again this time.