What does 'insir' mean, and what will be my source of funds like any job or other in Ireland?

insir' likely refers to the Irish Naturalisation and Immigration Service (INIS), which manages visas and immigration for Ireland.

For your study abroad application, you can show your source of funds through:
- Personal savings (your bank statements)
- Family support (parent/guardian bank statements, consent letter, and proof of relationship)
- Education loan (loan approval letter)
- Financial sponsorship (official sponsorship letter)

With your work experience, you may also include salary slips as proof of income. Funds generally need to be held for at least 28 consecutive days before your visa application. The exact amount and documents required are subject to change and depend on your chosen country and university.