An individual who is not a member of either House of Parliament may be appointed to the Council of Ministers; however, they must become a member of either House within a specified time frame of:

The correct option is 6 Months.

According to Article 75(5) of the Constitution of India, a minister who is not a member of either House of Parliament (Lok Sabha or Rajya Sabha) for any period of six consecutive months shall, at the expiration of that period, cease to be a minister.
This constitutional provision ensures that while an individual can be appointed as a minister or even the Prime Minister without being an elected member of Parliament at the time of appointment, they must secure a seat in either the Lok Sabha or the Rajya Sabha within a democratic grace period of six months to continue in office.