which is easier emcet or jee mains

it all depends on your preparation !!!!!
Basically, the main difference between EAMCET and JEE is, EAMCET is an engineering entrance examination which is only restricted to the state level, while the JEE is a national wide engineering entrance examination in which you may study engineering any where throughout the country.
but speaking of the difficulty level jee mains and advanced are much more difficult than eamcet.

Jee Main is a national level Engineering Entrance examination while EAMCET is a state level examination. So there will be differences in the level of both the exams. EAMCET is generally considered a level easier than Jee Mains but the syllabus is almost same and if you have prepared for Jee Main then you don't have to prepare again for EAMCET. Some tricky questions are asked. Studying NCERTs and IPE Textbooks , completing previous few years' question papers of EAMCET will help you to score good. Never leave any concept untouched and doubtful. If your basics are strong then it won't be difficult any more. Basic level questions are asked. And if you go through Previous year exam papers you'll understand it better.