The National Investigation Agency (NIA) has made a breakthrough in the Rameshwaram Café blast case with the arrest of a key conspirator. The arrest came after the NIA conducted raids in multiple states. The blast, which occurred at Rameshwaram Café in [location], resulted in [number] deaths and [number] injuries. The NIA is now interrogating the suspect to gather more information about the motive and the other individuals involved in the blast. The agency is also working to uncover any potential links to terrorist organizations.