As per your request, I am giving you contact details of the some best institutes in Delhi for the boxing classes. Have a look on following details.

Sanshinkan Martial Arts & Fitness Pvt. Ltd.
No. D-11/40, Sector 8, Rohni East Metro Station Pillar No. 377
Rohini
Delhi - 110085

Sanshinkan Mixed Martial Art & Fitness Pvt. Ltd.
No. N-8, Merto Pillar No. 86
Kailash Colony, Greater Kailash
Delhi - 110048

Martial Art Training Center
Sector 5, Krishna Apartment
Dwarka
Delhi - 110075

Combat India
South Extention Part 2
Andrews Ganj
Delhi - 110049

Sansinkan Martial Arts & Fitness Pvt. Ltd.
No. S-4/42, Old Mahavir Nagar, Janakpuri East Metro Pillar No. 553
Tilak Nagar
Delhi - 110018

FIGHTERS BOXING ACADEMY
F2/161 Mahavir Enclave, Nasir Pur Road, New Delhi-110045,,
Mahavir Enclave Part 2, Mahavir Enclave,
New Delhi, Delhi 110045 ‎
011 2505 2505 ‎

knock out delhi
629A, Opp- Polka Bakery, Shiv Nagar,
JanakPuri, Near-Mira Model School/Tilak Nagar Metro Station,
New Delhi, Delhi 110058 ‎
099990 53185

Kickboxing-Martial Arts Classes

N-8, Kailash Colony Metro Station, Pillar no 86,,
Lala Lajpat Rai Road, East of Kailash,
Kailash Colony, Delhi 110048 ‎
088262 30330

Invictus Self Defense & Fitness
St. Marys School, B-Block, Safdarjung Enclave,
New Delhi, Delhi 110029 ‎
099993 18007

Mixed Martial Arts
JanakPuri, New Delhi, Delhi ‎
096507 44123

weebly
A-13, Lajpat Nagar-2, New Delhi,
Near-Lajpat Nagar Metro Station Gate No-2,
New Delhi, Delhi 110024 ‎
085271 55852

Muaythai Classes Training Delhi
Jail Road, New Delhi, Delhi ‎
099716 62774

ISO solid gyms
20 / 40, Second Floor, West Patel Nagar,
Near Patel Park, New Delhi, Delhi 110008
011 4758 0367

Knockout Martial Arts Academy
WZ-629 A, Shiv Nagar Extn., Jail Road, Janakpuri, New Delhi, Near- Tilak Nagar Metro Station/ Meera Model Schools, Block BE, Shiv Nagar, Janak Puri, New Delhi, Delhi 110058 ‎
096549 15373

Martial-art
A-13, Basement, Lajpat Nagar-2, New Delhi,
Near- Lajpat Nagar Metro Station Gate No.2, Lajpat Nagar, Delhi 110024 ‎
099990 53185