Union Government
(1) No person shall be a member of both Houses of Parliament, and Parliament shall provide by law for vacating one seat. (2) No person shall be a member both of Parliament and a State Legislature; if elected to both, their Parliament seat becomes vacant after a prescribed period unless they resign the State seat first. (3) A member's seat becomes vacant if they become disqualified under Article 102, or if they resign in writing and the resignation is accepted (and is genuinely voluntary). (4) If a member is absent from all meetings for 60 days without permission, the House may declare the seat vacant.
An MP cannot simultaneously hold a seat in both Houses of Parliament, or in Parliament and a State Legislature at the same time - they must give one up. A seat also becomes vacant if a member becomes disqualified, resigns (genuinely and voluntarily), or is absent from the House for 60 consecutive days without permission.
If a sitting Rajya Sabha member is also elected as an MLA in their state, they must resign one of the two positions - holding both simultaneously is not constitutionally permitted.