The Services side pulled ahead after a close first quarter which went 23-22 in their favour.
They dominated the second, winning it 27-10 and shut out the Railways.
The final quarter saw Railways rally but that wasn't enough to stop Services from booking a spot in the final tomorrow.
Narendra Grewal with 18 points led the Services charge while Gagandeep Singh (18 points) fought hard for the rival side.
In the women's semi-finals, Indian Railways knocked out holders Kerala 76-63 to set up a title clash with Chhattisgarh, a 79-78 winner against Karnataka.
Navaneetha was the top scorer for Railways with 21 points as they accumulated points to maintain the pressure on the rivals.
Grima Mercin was the top scorer for Kerala with 21 points.
In the other last four encounter, Chhattisgarh squeezed home, thanks to some consistent play.
Poonam Chaturvedi led the way for the winning team, with a tally of 44 points.
Captain H M Bhandavvya with 25 points did the bulk of the scoring for Karnataka.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)