Hey Prafull, Temperature in shimla and manali would be somewhere below 5 in Jan and Feb ... it's good that you people carry proper clothing with you so that you can beat cold and enjoy your stay ... Apart from shimla and manali you can also check out for these Places Bro .... Darjeeling in West Bengal Coorg in Karnataka Aleppey and Munnar in Kerala Kodaikanal or Pondicherry in Tamil nadu you can also opt for Islands like andaman and Nicobar and also Lakshadweep for that matter ... Happy Travelling Bro!!!
So the temperature in Manali, Shimla or anywhere in Himachal would be in single digits and it'll be freezing cold. I advice you to be prepared for that kind of cold and take proper clothing congratulations for your wedding tho bro! :)