Hey Manesh,
Thanks for the question. The following resource provides some great information if you have having trouble using AirDrop in OS X Yosemite:
Mac Basics: AirDrop lets you send files from your Mac to nearby Macs and iOS devices - Apple Support
http://support.apple.com/en-us/HT6510
Don't see who you're looking for?
When you select AirDrop, OS X looks for other Mac computers and devices that are nearby that also use AirDrop. If you don't see someone in the AirDrop window, here are some things to check.
Preventing senders
You can prevent people you don't know from sending you files, or you can allow everyone. If you don't see a recipient in the AirDrop window, they might only accept files from people who in their Contacts list. Ask them to add you in their Contacts app, or have them select the option "Allow me to be discovered by: Everyone" in the AirDrop window.
Sending files to and from an older Mac
If a Mac you're using with AirDrop was manufactured before 2012, you can send and receive files with other Mac computers.
- On the sending Mac, click "Don't see who you're looking for" in the AirDrop window.
- Select the option to "Search for an Older Mac."
- On the receiving Mac, open a new Finder window and click AirDrop in the sidebar.
Tips for sending files
- Make sure Wi-Fi and Bluetooth are enabled on your Mac and your iOS device. Although you don't have to connect to a specific network, Wi-Fi needs to be on to send and receive files using AirDrop.
- Move your devices closer together. AirDrop is designed to work within a range of approximately 30 feet (9 meters). If you need to send a file to someone farther away, consider using File Sharing, iCloud, or email instead.
- If you're using a firewall on your Mac, you won't be able to receive AirDrop files if you have enabled "Block all incoming connections" in the Security & Privacy pane of System Preferences.
- Make sure your devices meet system requirements for AirDrop.
Thanks,
Matt M.