Step 1: Understand the question.
We must find the year when fitting High Security Registration Plates (HSRP) became compulsory for all new vehicles under the Motor Vehicles Act, 1988.
Step 2: Know what an HSRP is.
An HSRP is a special aluminium number plate with security features like a hologram, a laser-etched permanent number, hot-stamped film, and a snap lock. These make tampering very hard.
Step 3: Know why it was brought in.
The government wanted one uniform plate system across India to stop vehicle theft, prevent duplicate numbers, help track stolen vehicles, and improve transport records.
Step 4: Recall the implementation.
Using powers under the Motor Vehicles Act and the Central Motor Vehicles Rules, the government ordered that all new vehicles must come with a factory-fitted HSRP from a fixed date.
Step 5: Fix the date.
The Ministry of Road Transport and Highways made HSRP compulsory for all new vehicles from 1 April 2019. So the year is 2019.
Step 6: Check the options and answer.
2023 and 2024 are too late, since the rule was already running. 2018 is too early, as the nationwide mandate had not yet started. So 2019 is correct.
\[ \boxed{\text{2019}} \]