What is Bharat stage VI?

Bharat stage is  emission control standard which is launched by India at the year 2000.This is the standard which allows to keep in check of vehicle pollution.There is  Euro emission standard for Indian vehicles before the introduction of Bharat stage.
Bharat stage is Regulated by central pollution control board under Government of India.There is always an up gradation like BS I,BS II, BS III,BS IV.In 2016,Government decided to introduce BS VI instead of BS V due to high Vehicle pollution in country.This made India to compete with U.S.A,Europe and other countries in terms of emission control.
What are the changes we can expect from BS VI?
1)the major change is fuel,in which sulphur content is reduced by 5 times compared to BS IV.
2)NOx content is also reduced by 75% in diesel and 25% in petrol.
3)Introduction of On Board diagnostic systems by which fuel emissions can be greatly reduced
What are the changes can we expect in engines Due to Bharat stage VI?
1)introduction of diesel particulate filter and selective catalytic reduction
What About old BS IV vehicles?
There is no Problem for older vehicles,they can use BS VI fuel.It can even reduce pollution from older vehicles.
Is Vehicles may become costly?
Slightly but not major increase.It is also due to advance technology.
What about performance?
1)Performance increases due to low sulphur content in fuel by which life span of engine oil increases and also we can expect slightly low noise from vehicles.