The decision-making process in the GST Council involves several steps and requires a two-thirds majority vote. The GST Council is a constitutional body that consists of representatives from both the central and state governments. It is responsible for making important decisions related to the Goods and Services Tax (GST) in India.

1. Composition of the GST Council:
- The GST Council is chaired by the Union Finance Minister and includes the Minister of State for Finance and the finance ministers of all the states and union territories with legislatures.
- The central government holds one-third of the votes, while the states collectively hold two-thirds of the votes.

2. Decision-Making Process:
- All decisions in the GST Council are made by voting. Each member has one vote. The voting can be done either in person or through a proxy.
- The decisions are made based on a two-thirds majority, which means that at least 75% of the weighted votes need to be in favor of a particular decision.
- This ensures that decisions are taken in a democratic and consensus-based manner, taking into account the views and interests of both the central and state governments.

3. Weightage of Votes:
- The votes of the central government have a weightage of one-third of the total votes cast, while the votes of the state governments collectively have a weightage of two-thirds.
- This weightage system ensures that the central government's vote alone does not have the power to decide the outcome of a decision. It gives a higher weightage to the states, reflecting the federal nature of the GST framework.

4. Role of the Chairperson:
- The Chairperson, who is the Union Finance Minister, plays a crucial role in the decision-making process. They preside over the meetings, maintain order, and facilitate discussions.
- While the Chairperson does not have a casting vote, their role is significant in guiding the discussions, seeking consensus, and ensuring that all members have an opportunity to express their views.

In conclusion, the decision-making process in the GST Council requires a two-thirds majority vote, with the central government and state governments collectively holding the voting power. This ensures that decisions are made in a democratic and inclusive manner, taking into account the interests of both the central and state governments.