Q: I am unable to airdrop from my macbook pro retina early 2015 OS  X EL Capitan to iphone 5s ios 9.2! Although airdrop on both have been activated but the devices are not detecting each other! what can be the possible problem?

Hi Siddhant30,

I understand that you are running into some issues with AirDrop on your devices. I have an article for you with some tips on sending files that you may find useful, and it can be found here:

Tips for sending items

If you don't see the recipient in the AirDrop window or sheet:

• Make sure that both devices have AirDrop turned on and are within 30 feet (9 meters) of each other.
• If you're sending to an iPhone, iPad, or iPod touch: 
   
  • Your Mac needs to be a 2012 or newer model with OS X Yosemite or later.
   
  • The iOS device must have Personal Hotspot turned off in Settings > Cellular. 
• If you're sending to a Mac: 
   
  • If the receiving Mac is using OS X Mavericks, Mountain Lion, or Lion, it needs to have an AirDrop window open: choose Go > AirDrop from the menu bar in the Finder. 
   
  • If the receiving Mac is a 2012 or older model, click “Don't see who you're looking for?” in the AirDrop window or sharing sheet of the sending Mac. Then click “Search for an Older Mac.” 
   
  • Find out if the Mac has “Block all incoming connections” turned on in Security & Privacy preferences. A Mac won't receive items using AirDrop if this setting is turned on.
• If AirDrop on the receiving device is set up to receive items from contacts only, make sure that both devices are signed in to iCloud. Also make sure that the email address or phone number associated with your Apple ID is in the Contacts app of the receiving device.

Use AirDrop to send content from your Mac - Apple Support

https://support.apple.com/en-us/HT203106

Take care, and thanks for visiting the Apple Support Communities.