This thread appears to be related to Indian rail systems, specifically the LED signals used to safely direct the train engineer along the tracks. The nomenclature used for the relays may be unfamiliar. For example, the "back contacts" refer to normally-closed contacts when the relay coil is de-energized; "front contacts" refer to normally open contacts that close when the relay is energized. More information can be found in
this PDF article here.
The LED railroad signals operate from AC or DC, probably at 250 V but maybe less. I suspect (but have no way to be certain) that pairs of LEDs connected in inverse-parallel are used in these signals, with several of the pairs connected in series strings to obtain the overall voltage specification. Of course each string would need its own current-limiting resistor. In the USA LED traffic lights contain perhaps fifty to a hundred LEDs, depending on size, and may be retro-fits to incandescent lamp signals that are controlled (remotely) from 115 V AC control boxes. I think the "dummy load" should emulate an actual LED signal in terms of applied voltage causing a certain specified current. The LEDs should consist of at least one inverse-parallel connected pair (for AC operation) with an appropriate current-limiting resistor and LED power rating for the anticipated test current.
It is unclear how the test set will be used. How is it powered? How is the LED signal to be disconnected from its control relay to allow testing? Is the only purpose of the dummy load to ensure the test set is operational? Why use a relay coil at all to essentially measure continuity of the LED signal?