What's the best place in hyd to chill, since khajaguda hills is closed now

What kind of chilling do you mean. Because AFAIK khajaguda hills provide good amount of privacy for Couples to 'chill'

Hill near Qualcomm office beside near my home bhooja

Isn't home an option anymore?

What do you mean by “chill”? You can chill in a bar too, and in a large park too, it is upto you what you like. Like go to KBR Park, or Lotus Pond, or you can go to Pubs if you prefer drinking and partying