Yup, the last series lost was against England in 2012 so at home, for Indians it has been 12 years since the last test series defeat. A total of 17 series won in this period, the longest winning streak for any team in test cricket. The second best is the 10 test series (Australia). Someday they will lose for sure because it's bound to happen but it's a mighty achievement.
Cheery on the top would be, Australia not winning any test series against India since 2014-15. It might change in the upcoming BGT though.
Correction: 4 tests (I made a mistake when I said 3 tests)** 2 against Australia and 2 against England.
Amazing achievement indeed. England or Australia are the only ones capable of breaking such an insane record if you ask me. MSD kicked it off while Kohli took it a notch higher and Rohit took it another notch higher.
What would the Indian team be like without this super trio across all formats. Wonder how much longer Kohli and Rohit can keep playing for the country.