I have completed 12th and now want to give IIT JEE (Indian Institute of Technology Joint Entrance Examination) and looking for details about it so please provide me the same? Also tell me that how many seats are available in each IIT in India for IIT JEE Students?

As per your concern will let you know Joint Entrance Exam Advanced (JEE Advanced), reservation seats so that you can get idea easily.

Reservation seats
Other Backward Classes belonging to the Non-Creamy Layer (OBC-NCL)
27% of seats in every course

Scheduled Caste
15% of seats in every course.

Scheduled Tribe
7.5% of seats in every course.

Persons with disabilities
3% seats in each of OPEN, OBC-NCL, SC and ST category seats.

De- Reservation
Candidates belonging to the OBC-NCL, SC, ST and PwD categories will be declared as qualified on the basis of relaxed criteria

Eligibility Criteria for JEE Advanced Counselling and Seat Allotment 2017
In order to participate in JEE Advanced 2017 counselling, the examinees need to have secured the acceptable rank in JEE Advanced 2017.

They are required to have obtained at least 75% aggregate marks in class 12th or equivalent board exam. For candidates belonging to SC, ST and PwD categories, the aggregate marks required for admission is 65%.

OR
For admission to IITs, the candidates must be within the category-wise top 20 percentile of successful candidates in their respective class 12th or equivalent board exam.

Documents required
JEE Advanced 2017 Seat Allotment letter from JoSAA portal

JEE Advanced 2017 Original Admit card

JEE Advanced 2017 Application Form (duly filled)

Duly filled Medical Examination Report

Proof of Date of Birth: Class X/HSC/Birth Certificate/Any other certificate as proof of date of birth

Class XII/SSC/Equivalent exam Mark sheet and Certificate of passing

Category Certificate (OBC (NCL)/SC/ST/PwD/DS) issued by the competent authority

For foreign nationals: Attested photocopy of the page in the passport containing name, photo and nationality