Previous sanction of the President of India is required before introducing a bill in the legislature of a state that aims to impose reasonable restrictions on the freedom of trade, commerce, and intercourse within that state. This requirement is based on the constitutional provisions of India.

Explanation:

1. Constitutional Provisions:
The Constitution of India provides for a federal system of government, where powers are divided between the central government and the state governments. The legislative powers of the states are enshrined in the State List (List II) under the Seventh Schedule of the Constitution.

2. Public Interest and Restrictions:
The freedom of trade, commerce, and intercourse within a state or with that state is guaranteed under Article 301 of the Constitution. However, this freedom is not absolute, and reasonable restrictions can be imposed in the public interest. These restrictions may be necessary for various reasons such as protecting public health, morality, security, and economic development.

3. Requirement of Sanction:
According to Article 304 of the Constitution, any bill seeking to impose restrictions on the freedom of trade, commerce, and intercourse within a state or with that state requires the previous sanction of the President of India. This provision ensures that the exercise of legislative power by the states does not result in undue interference with inter-state trade and commerce.

4. Role of the President:
The President of India is the constitutional head of the country and exercises executive power on behalf of the Union government. The requirement of previous sanction from the President ensures that the central government can oversee and regulate any proposed restrictions on trade and commerce within the states. It also provides an opportunity for the central government to assess the potential impact of such restrictions on inter-state relations and the overall national economy.

5. Governor and Speaker's Role:
While the Governor of the state and the Speaker of the Legislative Assembly play important roles in the functioning of the state legislature, their prior sanction is not required for introducing a bill of this nature. The Governor's role primarily involves giving assent to bills passed by the legislature, while the Speaker's role is to preside over the proceedings of the Legislative Assembly.

In conclusion, the previous sanction of the President of India is required before introducing a bill in the legislature of a state that aims to impose reasonable restrictions on the freedom of trade, commerce, and intercourse within that state. This requirement ensures proper oversight by the central government and upholds the balance between state autonomy and national interests.