Avalon is an american market car and has an ecu tune for fuel containing 10% ethanol and 87 MON rating, it is also quite a lot heavier than camry too (which it is based on)
Supra is easier as its global car but its a bmw so buyer beware.
Both cars wont be servicable in Pakistan by toyota, specially avalon whose body, interior and finish parts are 100% usa made, meaning they dont exist in global catalogs and importing body parts is fever nightmares