When looking for a flats in Delhi, some localities are often considered less desirable due to various issues:

1. Seelampur: Overcrowded with poor sanitation and frequent power cuts.
2. Anand Parbat: Industrial area with high noise and pollution levels.
3. Narela: Outskirts with poor connectivity and limited amenities.
4. Bawana: Industrial zone with pollution and inadequate infrastructure.
5. Jahangirpuri: Overcrowded, with high crime rates and poor waste management.
6. Okhla Industrial Area: High pollution and traffic, unsuitable for residential living.
7. Kirari Suleman Nagar: Congested, frequent water and power shortages, safety concerns.
8. Trilokpuri: History of communal tensions, poor infrastructure and sanitation.

Always visit and assess any area personally to ensure it meets your needs and preferences.