There are certain requirements that you will need to meet before you can be granted indefinite leave to remain which are all indicated in the immigration rules:

The applicant must not fall for refusal under the general grounds for refusal, and must not be an illegal entrant.
The applicant must have spent a continuous period of 5 years lawfully in the UK, of which the most recent period must have been spent with leave as a Tier 1 General migrant, and the rest may be made up of leave:

  1. As a Tier 1 (General) Migrant,
  2. As a Highly Skilled Migrant,
  3. As a Work Permit Holder,
  4. As an Innovator,
  5. As a Self-Employed Lawyer,
  6. As a Writer, Composer or Artist.

The applicant must be economically active in the United Kingdom, in employment or self-employment or both.
The applicant must have sufficient knowledge about life in the United Kingdom, with reference to paragraphs 33B to 33F of these [immigration] Rules, unless the applicant is under the age of 18 or aged 65 or over at the time the application is made.

As also stated in the immigration rules, a Tier 1 (General) migrant will be refused application if he or she does not meet the requirements given above. An alternative action in this situation would be to qualify for leave to remain by virtue of paragraphs 33E to 33F of the immigration rules which state additional requirements by which an applicant can be granted indefinite leave to remain.