I am looking to buy a private and secure phone , unfortunaely pixel is not available in region , so looking over to buy iphone se , is there any drawback of choosing iphone se over iphone security and privacy wise?
Unlikely. Aim to get recent hardware as it will be supported for longer by Apple.
Security should be the same, but the hardware of iPhone SE is bad, and the value is bad too. I would recommend you to consider base models and avoid SE.
Basically the only security implications are related to the chip. The more recent the chip, the more secure it is generally, You’re getting the same chip as the iphone 13 which isn’t old by any means but it’s not the most recent one. I’d say you don’t really need to worry about it as long as the device is still getting OS updates though.