If it is run by Army Welfare Trust (AWT) then it is real. But Askar Leasing is no more in car leasing/financing business. Now it is Askari Bank which does car financing and leasing.
This could be another private group, so you do not know about its reliability. Better get your car from any reputable and well known bank like Askari, Alfalah, Meezan, Dubai Islami, HBL, UBL, MCB, Burj Bank, Summit, Soneri etc .