Check on google or ask any local member from Rajasthan , why not a train should halt at Sikar ? Sikar is the largest city between Churu and Reengus route and presently all the MG trains going via this route halt at SIKR.
And you have bypassed Ajmer city via Madar Jn. bypass which is only for Freight trains. Check the station map of Ajmer station if still not understanding.
Just tell me can any train bypass ajmer city ?