If we take a loan for studies abroad, how much should be shown in the bank account for visa purposes in UK/UAE?

It depends on the country and your university's location.

For the UK:
You must show enough funds to cover your first-year tuition fees plus living expenses for up to 9 months:
- Outside London: £1,171/month (up to £10,539)
- In London: £1,529/month (up to £13,761)

If using an education loan, it must:
- Be in your name
- Be from a recognized lender
- Clearly state the amount and be available unconditionally
- Be dated within 6 months of your application

Funds (loan and/or savings) must cover the required total and be held for at least 28 consecutive days, with the bank statement dated within 31 days of your visa application. These requirements are subject to change.

For the UAE:
Financial requirements vary by institution and emirate. You usually need to show enough funds for tuition and living expenses, typically via a bank statement or official letter from a recognized financial institution. Amounts and documentation can differ.