As you have asked about the institutes offering IIT crash course in Chennai, I am mentioning some of them, check below for the details

TRS IIT CLASSES
Coaching Center
Address: 37/72, 7th Avenue, Ashok nagar, (opp. GRT School Play Ground),, Chennai, Tamil Nadu 600083
Phone:094443 61199

SRG Foundation
Training Centre
Address: 70 5th, 33, 11th St, Z Block, Kathiravan Colony, Anna Nagar, Chennai, Tamil Nadu 600040
Phone:094441 83955

Appolo Academy
Training Centre
Address: 8/1, First Floor, Kamaraj Nagar, Thirvalluvar Salai Thirvanmiyur, Near Adyar Bakery, Chennai, Tamil Nadu 600041
Phone:044 6565 5454

Brilliant Tutorials
Corporate Office
Address: 12, Masilamani Street, Thyagaraya Nagar, Chennai, Tamil Nadu 600017
Phone:044 2434 2099

FIITJEE
Coaching Center
Address: 175, Poonamallee High Road, Opp Ega Theatre, Kilpauk, Chennai, Tamil Nadu 600010
Phone:044 4285 9701

Bansal Classes Annanagar
Computer Training School
Address: T.R.R Complex, Door #47, F Block,, 2nd Floor, 1st Main Road, Annanagar East, Tamil Nadu 600102
Phone:095511 44044

Fiitjee
Training Centre
Address: New no. 11, 29th Cross Street, Indira Nagar, Adyar, Chennai, Tamil Nadu 600020
Phone:044 4395 0450

T.I.M.E. Chennai
Coaching Center
Address: 110/ 3rd Floor, Arcade Center, Above SBI,, 116/1, Nungambakkam High Rd, Subba Road Avenue, Nungambakkam, Chennai, Tamil Nadu 600034
Phone:044 4300 9797