Married/ Civil Partners:
If you have spent 5 years in the UK on Family visa, you would be eligible to apply for permanent residence.
You would need to pass Life in the UK test and meet the English language and minimum income requirement.
Once you have been granted ILR, you can apply for ‘naturalisation’ straight after.
Tier 2 General:
You could be eligible to apply for ILR, if you have spent 5 years under Tier 2 General category (provided you meet the income criteria, still in the employment and your employer is supporting the application)
10 year legal in UK
If you have been living in the UK, lawfully for at least 10 continuous years, you might be able to apply for ILR (Indefinite Leave to Remain). You should not be outside the UK for more than 540 days in total and more than 180 days at any one occassion.
You can be in the UK in one visa category or a combination of different visa categories.
You will need to meet ‘Life in the UK Test’ and minimum English language requirements.