I'd suggest Mehran for a salaried person who wants a vehicle he can use reliably.
In the given budget, get your hands on a mehran and leave at least 50,000 Rs cash with you for repairs and maintenance.
The best part about mehran is cheap spares and the difference is immense.
Get compression test and install new rings/pistons or overhaul if required, head gas kit problem is also very common.
Checking and installing a new radiator would be a very good thing, along with all pipes and water body - use coolant always.
overhaul the brakes, get your brake calipers serviced, change the rings of brake pistons, change all the brake lines, service the master cylinder, replace the brake oil.
Get axles and whole steering assembly checked and repair it.
Service the CNG kit, get cylinder checked in high pressure, check the pipes.
Check the tires, replace if necessary and get wheels balanced.
Redoing all the electrical wiring is usually also very important in these old cars if u wona make them reliable.. otherwise you will always have starting troubles. New battery is mostly also required, get the car's generator serviced too.
Spending on all of these systems of a car is important, if u redo the engine and leave the wiring ur car still wont start.
If u redo the engine and leave the radiator.. chances are it would get ruined...
Thus each and every SYSTEM of ur car needs to be checked, reapired and revived.
With khayber, charade etc u can never afford that in this budget...
typically u will be facing all the above listed problems... include rusted gatri(engine supports) and what not! So forget it... every used machinery would need a lot of money and U would have a really bad time with any other car than mehran.
Even FX has a genuine Gatri(kabli) costing 8,000Rs and local 5,000Rs!
50Ks is minimum to keep a side for repairs.