Explanation:

The President of India (based on a recommendation from incumbent Govt of India) appoints the Chief Election Commissioner. Conventionally, senior-most Election Commissioner is appointed as CEC. He has tenure of six years, or up to the age of 65 years, whichever is earlier.
The Election Commission of India is an autonomous constitutional authority responsible for administering election processes in India. The body administers elections to the Lok Sabha, Rajya Sabha, state legislatures, and the offices of the President and Vice President in the country. The Election Commission operates under the authority of Constitution per Article 324, and subsequently enacted Representation of the People Act.