Yes

The phone doesn't have a simlock so it should work with any suitably sized SIM card. You need to check that the phone can use the frequencies in the country you are visiting. According to ChatGPT:

"The Xiaomi Redmi 9A supports the following network frequencies:

4G LTE Bands:
FDD-LTE:
B1 (2100 MHz), B2 (1900 MHz), B3 (1800 MHz), B4 (1700/2100 MHz), B5 (850 MHz), B7 (2600 MHz), B8 (900 MHz), B20 (800 MHz), B28 (700 MHz)

TDD-LTE:
B38 (2600 MHz), B40 (2300 MHz), B41 (2500 MHz)

3G Bands (WCDMA):
850, 900, 1900, 2100 MHz
2G Bands (GSM):
850, 900, 1800, 1900 MHz

These frequencies cover most global networks, but you should still confirm compatibility with specific carriers in the country you're planning to use the phone in. Some regions may rely on less common LTE bands not supported by this device."

You might encounter problems in parts of the USA, Canada, Japan, China and South Korea, but I don't think European countries should be a problem.

You didn't ask the question, but I found the phone response to be really slow.

yes. is the global version.