Is New Delhi a state of or city in Delhi?

From Wikipedia: New Delhi (/ˌnjuː ˈdɛli/) is the capital of India and one of Delhi city's 11 districts. Although colloquially Delhi and New Delhi are used interchangeably to refer to the National Capital Territory of Delhi, these are two distinct entities, with New Delhi forming a small part of Delhi. read more

New Delhi: New Delhi is the capital of India and neither a state, nor a Union Territory. The amendment declared the Union Territory of Delhi to be formally known as National Capital Territory of India. read more

New Delhi is a cosmopolitan city due to the multi-ethnic and multi-cultural presence of the vast Indian bureaucracy and political system. The city's capital status has amplified the importance of national events and holidays. read more

So basically Delhi is the City cum state cum capital of india, New delhi is the District of Delhi (and it is most developed area in delhi) and the NCR is the combinational area of many cities like delhi, noida, ghaziabad, Gurugram, Faridabad and meerut. read more