There isn’t a specific style that they built the Jama Masjid in, but it was built by a mughal empire. This mosque was built by Sultan Ahmed Shah in 1423, and then then later by Shah Jahan. Shah Jahan rebuilt the Jama Masjid and it was dedicated to his favorite daughter. It was also where the Mughal emperor lived for many years. It was constructed by more than 5000 workers. It was originally called Masjid-i-Jahan-Numa, meaning 'mosque commanding view of the world'. The construction was done under the supervision of Saadullah Khan, wazir (or prime minister) during Shah Jahan's rule. The cost of the construction at the time was 14970.860 US Dollar, which is probably MUCH more now.