* Lack of infrastructure: FM radio requires a network of transmitters and receivers in order to function. If there is not a sufficient infrastructure in place, then it may not be possible to broadcast FM radio signals in Jamnagar.
* Government regulations: The government may have regulations in place that restrict the use of FM radio in certain areas. For example, the government may have designated Jamnagar as a "silent zone" where FM radio is not permitted.
* Lack of demand: There may not be a sufficient demand for FM radio in Jamnagar. If there are not enough people who are interested in listening to FM radio, then it may not be economically viable for a broadcaster to set up a station.
It is also possible that there are other reasons why there is no FM radio in Jamnagar. If you are interested in finding out more, you may want to contact the local government or a radio broadcaster in the area.