In India, how can a non member of parliament become a Cabinet Minister, for how long and for how many terms?
The Cabinet minister is appointed by the Prime Minister.
A Minister ought to be a Member of either of the Houses and if not, he must get elected to the House within six months, failing which he shall not continue as a Minister. This is the only constitutional restriction, others being political in nature.
The houses referred are Lok Sabha (House of Commons) and Rajya Sabha (House of Lords in the UK parliament). Other political constraints being the Prime minister tries to give equal weight to different states, and in case of coalition government, different political parties.
Reference: Deogaonkar, Shashishekhar Gopal. Parliamentary system in India. Concept Publishing Company.