I had 1.5 year female rottweiler but it's not yet came to heat is her need medicine

Hi Adarsh! Rottweilers can be a bit unpredictable with their first heat cycles and it's not uncommon for some to have their first cycle after 1.5 years. Silent heats can also happen. Make sure she's on a well-balanced diet and if she doesn’t come into heat within next 3 months, consider a clinical examination and hormone analysis to check her reproductive health.