First of all, Thank you for asking the right Question.
You are the first "team" that is starting their homework by involving the End Users, the customer, first - right at the beginning, that tells alot about your group. You are on the right track, and please keep at this track by involving the Pakistani Public every step of the way, down to the marketing of this car one day, Insha_Allah.
Considering the market, the most selling car at this time is Suzuki Mehran. Due to its low cost, easy maintenance, reliability, and length of time in the market. People do not care for Airbags, Seatbelts, ABS, etc. at this segement, what concerns them is the cost and above mentioned factors.
So, you should start with a low-end car, smallest one with 800CC engine, make sure it is CNG ready, as cost of Petrol is very high and Pakistan happens to be one of most CNG driven country in the world, 3rd biggest in terms of all the cars running on CNG. OEM Parts should be easily available, that will not be a problem, as Govt, of Pakistan requires any existing or new Car maker to source local vendors for parts. It should be made with a price range of Rs. 150,000 to 200,000 before Taxes.
The car should have something to differentiate itself from the competition. Forexample, powerwindows (kits are available for Rs. 4,000 as I read somewhere), and will not add to cost of the car much but will gain customer's attention as they will think why should I buy this over Mehran or others.
Design should be from the 2005, much like AMC Revo, and not anything like Mehran, as most people are sick of that old 1980s look, but are forced to buy it, as its the only car they have in this segment yet, AMC Revo is still in the process of being introduced.
The colors should be attractive and final fit and finish of the car should, both the exterior and interior should be flawless, as Pakistanis notice even the smallest dent.
The interior should also be attractive specially the dashboard, as many Pakistanis are complaining of the dashboard of AMC Revo, which just got introduced.
If money is not the concern then go for a full fledge Sedan, with alteast 1300CC engine, designed after Honda Civic or Toyota Corolla.