UNA & DDN Jan-Shatabdi do have RSA!!
DDN-NDLS Jan Shatabdi, which arrives move forward as UNA Jan, while UNA-NDLS moves towards DDN!!
In winter, i dont think that either RAJ or Jan-Shatabdi are gonna run in-time!!
But still, Rajdhani is quite risky, if u have to catch Jan-Shatabdi, same day (as Raj has to traverse more distance in fog, as compared to Jan-Shatabdi, which...
more... have its most run in day)!! If u dont have work @ NDLS, but use Raj/Jan only @ NDLS, then better travel by other option till Ambala (via MB Route) or else think of Bus/Cab-Journey for NDLS-CDG, which is quite faster!!