The law in India can be divided in 2 basics laws:
Section 6 CrPC, categorises the Criminal Courts as follows:
The powers, position & role of various courts:
High Court
High Court is the highest court exercising criminal jurisdiction in a state. It hears appeal from District & Session Courts. Though, it has original jurisdiction in some matters but predominantly, it is for hearing appeals from the District & Sessions Courts. It can pass any sentence authorised under law including Capital punishment (Death Sentence). But the most important function that is performed by High Court is it exercises administrative control over the District Courts. So, all the District courts are within the administrative control of High Court.
The Sessions court
The next court under the hierarchy is the Court of Sessions (Section 9-10 CrPC). Courts of Sessions are established by State Governments in every sessions division. CrPC categorises every district in a state into one session division and for each of a session division there is a provision of Session judge. The Session judge is the judge who presides over the court of Sessions. The court of Sessions is subordinate to the High Court and it can pass any sentence authorised under law in force {Section 28(1)} but a sentence of death has to be confirmed by the High Court {Section 28(2)}.
Judicial Magistrate First Class/ Metropolitan Magistrates/District Judges
The next court under the hierarchy is the courts of Judicial Magistrate First Class/ Metropolitan Magistrates (Section 11-14). Judicial Magistrate First Class or Metropolitan Magistrates in a district is appointed by the High Court. The senior most Judicial Magistrate of First Class is designated as the Chief Judicial Magistrate. He heads the Magistracy in the district. The Chief Judicial Magistrate can pass any sentence authorised by law, except a sentence of death or life imprisonment or imprisonment exceeding 7 years {Section 29 (1)}.
The High Court may also appoint Additional Magistrates in any district in order to assist the Chief Judicial Magistrate (CJM). Additional Magistrate can pass any sentence of imprisonment not exceeding 3 years or of fine not exceeding fine of Rs. 5000 thousand or both {Section 29(2)}.
Judicial Magistrate Second Class
Judicial Magistrate Second Class (Section 15 CrPC) are appointed by High Court and they can pass any sentence of imprisonment not exceeding 1 year or of fine not exceeding Rs. 1000 or both {Section 29(3)}.
Executive Magistrate
An Executive Magistrate is an officer of the Executive branch (as opposed to the Judicial branch) who is vested with specific powers under both the CrPC and the Indian Penal Code (IPC). Technically, the police are to assist the Executive Magistrate.