Which commission's recommendations formed the basis for the Punjab Reorganisation Act that created the states of Punjab and Haryana?

Introduction / Context:
This question deals with the reorganisation of states in India, specifically the creation of the modern states of Punjab and Haryana. Various commissions have been appointed at different times to examine state boundaries and linguistic or administrative issues. Identifying the correct commission associated with the Punjab Reorganisation Act is a typical question in Indian polity and modern history.

Given Data / Assumptions:

• The focus is on the Punjab Reorganisation Act, which led to the creation of Punjab and Haryana.
• Several commissions are listed as options.
• We assume some familiarity with the history of linguistic reorganisation and boundary commissions.

Concept / Approach:
The Shah Commission was appointed to look into reorganisation issues in the Punjab region, including demands for a Punjabi speaking state and a Hindi speaking state. Its recommendations formed the basis of the Punjab Reorganisation Act of 1966, which created the states of Punjab and Haryana and made Chandigarh a union territory. Other commissions such as the Dhar Commission were involved in earlier studies on linguistic states, but not specifically in this Act.

Step-by-Step Solution:
Step 1: Recall that the Punjab Reorganisation Act came into force in the 1960s, resulting in the creation of Punjab and Haryana. Step 2: Remember that the Shah Commission was set up to recommend how the region should be divided. Step 3: Compare this knowledge with the options, which include Dhar, Dass, Shah and Mahajan Commissions. Step 4: Identify the Shah Commission as the one whose report led directly to the Act. Step 5: Select Shah Commission as the correct answer.

Verification / Alternative check:
An alternative check is to associate the Dhar Commission with early discussions on linguistic states in the late 1940s, while the Shah Commission is remembered specifically in connection with Punjab and Haryana. The Mahajan Commission is often mentioned in connection with other boundary disputes, not with the main Punjab reorganisation.

Why Other Options Are Wrong:
Option A (Dhar Commission) is incorrect because it was an earlier commission that examined the question of linguistic states in general, not specifically the Punjab Haryana division.
Option B (Dass Commission) does not match the well known historical account of how the Punjab Reorganisation Act was framed.
Option D (Mahajan Commission) is associated with other boundary issues and is not the basis for the Punjab Reorganisation Act of 1966.

Common Pitfalls:
Students often confuse various commissions because of similar sounding names and overlapping time periods. A useful memory aid is to link Shah Commission with the reorganisation of Punjab and Haryana and with the controversy over Chandigarh as a shared capital and union territory.

Final Answer:
The recommendations of the Shah Commission formed the basis for the Punjab Reorganisation Act that created the states of Punjab and Haryana.