No, its not an April fool prank.
BS-VI is equivalent to EURO-VI grade fuel having mere 10parts per million of sulphur against the 50 ppm of BS-IV.
In 2015, India had made decision to skip the BS-V norm and dive head first to walk the talk of showing its INDC (Intended Nationally Determined Contribution), drawing the spirit from UNFCCC meet, COP21.
For now, the cleaner fuel is available only in and around the National Capital, because the air condition in this place is one of the most worst affected by emission pollution along with burnt crop residue from neighbouring states, building material dust and acute weather conditions which lead formation of smog.
Rest of the metro cities will have the fuel by next year and remaining far sub-urban regions by 2020 April.