What are parliamentary privileges?

• Parliament and its Members (MPs) have certain rights and immunities that enable them to function effectively in their legislative roles. These are called parliamentary privileges.
• Parliamentary privileges are a mix of provisions in the Constitution, statutes, House procedures and conventions. For example, the Constitution specifies that MPs have freedom of speech and immunity from judicial proceedings against anything they say or votes they cast in Parliament.
• Also, the Code of Civil Procedure protects them from arrest and detention under civil cases during a parliamentary session, and for a specified period before it begins and after it ends. Parliamentary rules specify that authorities should immediately inform the Speaker of Lok Sabha and Chairman of Rajya Sabha about MPs’ arrests, releases and convictions.
• Accompanying the question of privilege is the concept of Contempt of the House. Contempt is any act or omission which obstructs or impedes either House of Parliament in the performance of its functions, or which obstructs or impedes any member or officer of such House in the discharge of his duty, or which has a tendency, directly or indirectly, to produce such results may be treated as a contempt even though there is no precedent of the offence.

How does Parliament act on breach of privilege?

• Each House of Parliament is the guardian of its privileges. Lok Sabha and Rajya Sabha have the authority to take suitable action against anyone who breaches the privileges of its members or commits contempt of the House. 
• There are two mechanisms by which Parliament takes up these matters. The first is by a member raising the issue on the floor of the House, and then the House decides on it.
• But Lok Sabha and Rajya Sabha usually send the matter for a detailed examination to their Privileges Committee. The committee recommends to the House a course of action which is then accepted by it. The Chairman of the Lok Sabha committee currently is its MP Sunil Kumar Singh, and the Deputy Chairman of Rajya Sabha, Harivash, heads the committee of the upper House.
• MPs can also bring matters of breach of privilege to the notice of the presiding officers of their respective Houses. The presiding officers can then decide whether or not to send the case to the committee of privileges.

What does the committee decide in breach of privilege cases against MPs?

• The Committee of Privileges has the power to recommend to the House for its consideration the issuance of admonitions, reprimands, suspension and, in rare cases, expulsion from the House. 
• The convention followed by the committee of both Houses is that if the MP against whom a privilege matter is raised gives an unqualified apology, then the issue is allowed to rest, and it recommends no further action.
• In one rare case in 1978, the Lok Sabha committee on privileges recommended the expulsion of then Prime Minister Indira Gandhi. And the next Lok Sabha rescinded the earlier recommendation.

https://indianexpress.com/article/explained/lok-sabha-congress-adhir-ranjan-chowdhury-privileges-committee-explained-8887311/#:~:text=The%20Committee%20of%20Privileges%20has,cases%2C%20expulsion%20from%20the%20House.