Among the following tentatively named missions, which one is ISRO planning to…

Concept — ISRO names its planetary and solar missions after the Sanskrit or Vedic name of the body the spacecraft is sent to study, usually with the suffix “-yaan”, meaning “vehicle”. The destination is therefore encoded in the mission's own name, so identifying the Sanskrit name of a target body tells you which mission is aimed at it.

Application — In Sanskrit the planet Venus is Shukra, so “Shukrayaan” reads as “Venus-craft”. Shukrayaan-1 is the tentative name of the project whose official designation is the Venus Orbiter Mission (VOM): the Union Cabinet approved it in September 2024 and ISRO has scheduled the launch for March 2028, to study the planet's atmosphere, surface and its interaction with the solar wind.

Cross-check — Applying the same naming rule to the other three names sends each of them to a different body, so exactly one of the four is a Venus mission:

Result — The mission ISRO is planning for the exploration of Venus is Shukrayaan-1.