Ken Technology — fraud/fake

I got a call from this company. Being a student i got really happy that i'm getting a job and i didn't think much. But afterwards after registering and seeing their app mails and all it really seemed fake and cheap. I immediately messaged the woman who was in contact and asked her that i want to back out. They also put a condition that i have to do the work with 90% accuracy which is not possible in case of captachas as the difference between small l and capital i cannot be determined. Also it is in their hand how many captachas they wanna give green light. Now they sent me a mail asking to pay 6900 rs and threatening me to send a legal notice at my home. I'm really worried what to do? Will they really conduct legal proceedings against me?