In which part of the Indian Constitution are centre state relations mentioned?

The correct option is Part XI (Article 245 to 255).

Step-by-Step Explanation:

1. Understanding Centre-State Relations:
The Constitution of India establishes a federal structure, dividing legislative, administrative, and financial powers between the Union (Centre) and the States. These relations are primarily organized under different parts of the Constitution depending on their nature (legislative, administrative, or financial).

2. Constitutional Provisions:
Part XI of the Indian Constitution specifically deals with the relations between the Union and the States. This part is further divided into two chapters:
- Chapter I: Legislative Relations (Articles 245 to 255) which defines the territorial limits of legislative powers and the distribution of legislative subjects between the Centre and States.
- Chapter II: Administrative Relations (Articles 256 to 263) which deals with the coordination and control between the executive power of the Union and the States.

3. Analyzing the Options:
- Part XI (Article 245 to 255): This correctly identifies the part of the Constitution (Part XI) and the corresponding articles (Articles 245 to 255) covering the crucial legislative aspect of Centre-State relations.
- Part IV: Relates to the Directive Principles of State Policy (Articles 36 to 51).
- Part X: Relates to the Scheduled and Tribal Areas (Articles 244 to 244A).
- Part XII: Deals with Finance, Property, Contracts, and Suits (Articles 264 to 300A).

Therefore, the relations between the Centre and the States are constitutionally mandated under Part XI, starting from Article 245.