Catch a budget flight from Indira Gandhi International Airport (DEL) to Suvarnabhumi Airport (BKK), usually the cheapest and with many airlines offering affordable fares.
Stay at a safe, budget hotel like The Yard Hostel or similar, providing dorm rooms around 300-400 THB per night in popular nightlife areas like Sukhumvit.
This is the heart of Bangkok's nightlife with budget bars, street booze, and vibrant party scenes ideal for tourists seeking fun with relatively low risk.