A most often asked question for Engineering Entrance Exams 2017 is "Which Engineering can I take this year?" To this, here is an answer in brief
JEE Main 2017: This is the engineering entrance exam that CBSE conducts on all-India level. Almost all engineering aspirants appear for JEE Main. We advise you to take it as it opens up gateways to hundreds and thousands of engineering colleges. It also serves as a preliminary exam required for JEE Advanced.
JEE Advanced 2017 (formerly known as IIT JEE): This is a specific under graduation entrance exam for getting into IITs.
BITSAT 2017: BITS Pilani is mostly ranked among top engineering colleges in India, almost at par with the IITs in most respects. Admission to all campuses in BITS Pilani will be on basis of BITSAT.
UPSEE 2017: Uttar Pradesh State Entrance Examination is organized by APJ Abdul Kalam Technical University (AKTU), Lucknow in order to facilitate admission to Institutes affiliated to it. This is majorly an important exam for UP domicile students.
Likewise, one must appear in engineering entrance exam specifically for one's home state. You can mention your state in this thread and we can let you know important entrance exams for your home state.
EAMCET: Engineering, Agriculture and Medical Common Entrance Test is now held separately for AP and TS. This examination is a prerequisite for admission to all aforementioned courses.