In 2016, India became a member of the Missile Technology Control Regime (option 2). The Missile Technology Control Regime (MTCR) is an international voluntary partnership of countries that strive to prevent the proliferation of missiles and unmanned delivery systems capable of carrying weapons of mass destruction.

Let`s briefly look at the other options:

Option 1: Non-Proliferation Treaty (NPT) - India has not become a member of the NPT. The NPT is to prevent the spread of nuclear weapons, encourage disarmament, and enable the peaceful use of nuclear energy.

Option 3: Nuclear Suppliers Group (NSG) - India joined the NSG in 2016, along with several other countries. The NSG is a group of nuclear supplier countries that aims to control the export of nuclear materials and equipment.

Option 4: Wassenaar Arrangement - India joined the Wassenaar Arrangement in 2017, not in 2016. The Wassenaar Arrangement is a multilateral export control regime that regulates the transfer of conventional arms and dual-use goods and technologies.

Therefore, the correct answer is option 2 (Missile Technology Control Regime).