Stick to US consulate if you can, its very straightforward process . Also CIC website have clear instructions.
If you are a citizen of India:
If you live in India:
For residents of Punjab: You can apply to your local Senior Superintendent of Police, or the senior ranking police official at the police station in your district.
For residents of Delhi: You can apply at your local district police station or online on the
Delhi Police website. The website will list what information and documents you need. If you apply online, your certificate will be returned to you electronically.
For residents of other states: You can apply at your local district police station.
For all residents of India: You can apply for a Police Clearance Certificate from the Passport office on the
Passport India website. The website will list what information and documents you need.
If you live outside of India:
You can apply at your nearest Indian embassy or consulate.