Are side car motor bikes with a engine capacity of 750cc permitted on freeways and National roads, I am unable to find any reference in the National road traffic act.
The definition of a motor cycle in the Act is a motor vehicle having 2 wheels and includes any such vehicle having a side car attached.
Regulation 323 is special provisions relating to freeways.
Regulation 323 specifies that motor tricycles and motor quadrucycles are not allowed on a freeway.
Regulation 323 has limitation on motorcycles, viz that engine capacity should exceed 50cc and no electrically powered motor cycles or motor cycles having pedals or pedals and a motor and can be propelled by either or both are allowed on freeways.
Other than the above I too can find no other specific reference to motor cycles (including side car) not being allowed on freeways.
Also a National road is not necessarily a freeway. The definition of a freeway is any public road or section of a public road that has been designated as a freeway by an appropriate road traffic sign.