hey pramod,

Every year B.Tech entrance examinations are conducted throughout the nations in two ways online/offline. the common examination for every student interested in engineering is JEE. every state has it's own entrance examinations apart from JEE. coming to the syllabus part. the syllabus is same as your 12th starndard. only differs in difficulty level. B.Tech requires good command on Mathematics, Physics and chemistry. 

all the best :)