What should be the 1st financial year of a newly incorporated Company?

“Financial Year"

For any company or body corporate*: 
means the period ending on the 31st day of March every year.

For a newly incorporated Company: 
Where a Company has been incorporated on or after the 1st day of January of a year, the period ending on the 31st day of March of the following year.

Summary:
Thus, every Company or body corporate incorporated in India should follow the f.y. Commencing on 1st April and ending on 31st March, i.e. for 12 months

In the case of a newly incorporated  Company, which, if incorporated on or after 1st January of a year, can have its first financial statements prepared for more than 12 months- i.e. a maximum of 15 months.

Remember to use the word ‘period’ in the Board’s Report, Auditors Report and elsewhere, wherever the word ‘year’ is being used alongwith financial statements.
Ex: “The Directors of your Company present the Board’s report for the period (and not f.y) from 1st January 2020 to 31st March 2021….”

Holding/ Subsidiary/Associate Company# : 
A company or body corporate*, which is a holding company or a subsidiary or associate company of a company incorporated outside India and is required to follow a different financial year for consolidation of its accounts outside India, the Central Government may, on an application made by that company or body corporate in E-Form RD-1 alongwith required documentation, allow any period as its financial year, whether or not that period is a year:

*Body Corporate
Is ‘body corporate’ different from a ‘company’?

No. Not different but is a ‘larger’ concept as compared to a ‘Company’. Body corporate includes a Company incorporated under Companies Act,2013  of India or any other previous Act and Companies incorporated outside India.

"body corporate" or "corporation" 
includes a company incorporated outside India, but does not include—
(i) a co-operative society registered under any law relating to co-operative societies; and
(ii) any other body corporate (not being a company as defined in this Act), which the Central Government(CG) may, by notification, specify in this behalf;
Information:
The Asian Development Bank has been recently notified by the CG excluding it from the definition of body corporate or corporation

Its has been held that a body corporate has 5 distinct attributes:
The entity shall be different from its members
Perpetual succession
It must be competent to enter into a contract
Is capable to sue or being sued in its own name
Can hold the property in its own name

#"holding company", in relation to one or more other companies, means a company of which such companies are subsidiary companies. The expression "company" includes any body corporate.

#"subsidiary" in relation to any other company (that is to say the holding company), means a company in which the holding company-
●     controls the composition of the Board of Directors; or
●     exercises or controls more than one-half of the total voting power either at its own or together with one or more of its subsidiary companies

#"associate company", in relation to another company, means a company in which that other company has a significant influence, but which is not a subsidiary company of the company having such influence and includes a joint venture company.
 
#"significant influence" means control of at least twenty per cent. of total voting power, or control of or participation in business decisions under an agreement;

#"joint venture" means a joint arrangement whereby the parties that have joint control of the arrangement have rights to the net assets of the arrangement;