You will need to approach your schools for medicine and physiotherapy in pakistan to find out about the specific system in your country.
Here in NZ, it is entirely possible to do medicine following having done physiotherapy - however it is hard to get in because it's harder to get marks in physiotherapy... this is because it is marked subjectively on a practical exam, and when your competing against people who have done a degree in physiology for example that sat an objective exam and had ever possibility of getting 100% it makes your makes not as impressive in comparison.
So in NZ it's possible, and has certainly been done before. But what you need to do is approach the schools and ask them what the enterance requirements are and work towards acheiving those as they will be different to NZ.