There are several Hair Spa located in Delhi. I am providing complete address of best Hair Spa for your reference:

Address of Best Hair Spa in Delhi

Monsoon Salon & Spa  
83 First Floor,, 1, Club Rd, West Punjabi Bagh,
Punjabi Bagh, Delhi, 110026
Phone: 011 4314 2417

Blue Terra Spa Punjabi Bagh  
5 Club Road, 2nd Floor, Above Bank of Baroda,
Punjabi Bagh, New Delhi, Delhi 110026
Phone: 011 4557 7400

Monsoon Salon & Spa  
E-14, 2nd Floor, Above Oriental Bank of Commerce,
South Extension Market Part II, New Delhi, Delhi 110049
Phone: 011 4300 5700

Geetanjali Hair Salon  
41, Middle Cir, Khan Market, Rabindra Nagar,
New Delhi, Delhi 110003
Phone: 011 4105 9518

Alaya Spa + Salon  
No.9, PVR Anupam Complex, Community Center,
Opp HDFC Bank, Saket, New Delhi, Delhi 110017

Skin Allure Aesthetic Clinic
A-7, Phase-2, Above HDFC Bank, Ashok Vihar,
North Delhi, Delhi 110052
Phone: 011 4553 4432

Trendy MakeOver™ Family & Unisex Salon  
F90 1st Floor Above Karnataka Bank, Lajpat Nagar II,
Lajpat Nagar, Lajpat Nagar 2, Delhi 110024
Phone: 011 4143 6789

Monsoon Salon & Spa  
M 24, 1st & 2nd Floor, M Part II, M Block Road, Block M,
Greater Kailash II, Greater Kailash, New Delhi, Delhi 110048
Phone: 011 4300 5850