As tax will be imposed only after the date of the signing of the agreement between the two the treaty between India and Mauritius won't likely have retrospective taxation effect as per the news channel CNBC-TV18, on April 12. 

It is said that these new provisions pertaining to India-Mauritius treaty will apply to even past investments where the taxable event has occurred in the aftermath of the protocol. Having said that, CNBC-TV18 has also reported that it is not retrospective as taxability would only be post the date of the treaty; thereby coming into effect even in situations where the investments have been made at an earlier date.

Additionally, the news channel also stated that India will notify Mauritis on the protocol so as to make it applicable.

Including a principal purpose test (PPT) to decide whether a foreign investor is eligible to claim treaty benefits, India and Mauritius have signed a protocol to amend the double taxation avoidance agreement (DTAA).

Tax experts have said that a new article has been included in the protocol, i.e., "Article 27B Entitlement to Benefits". 

The rectified protocol was signed on 7th of March and was made public on April 10. By ensuring that treaty benefits are only granted for transactions with a bona fide purpose, the introduction of the PPT aims to curtail tax avoidance.