The tail fin used to be an essential part of an aircraft. Its presence ensures that the plane has a stable flight. But the presence of it is a major cause for fighter and bombers to be easily detectable on radar.
One option is to incline it at sharp angles, like in the F-117 Nighthawk.
The second option, now adopted in facilitating stealth features to such planes is by completely doing away with the tail fin. The stability of the flight is then controlled by plane's thrust vectoring capability, as it will be in India's MCA!