From the recent report the iOS 13 compatible devices are below

IPHONE

• iPhone 6S
• iPhone 6s plus
• iPhone 7
• iPhone 7 Plus
• iPhone 8
• iPhone 8 Plus
• iPhone X
• iPhone XS
• iPhone XS Max
• iPhone XR
  

  IPAD

• iPad Pro 12.9in first and second generation
• iPad Pro 10.5in
• iPad Pro 9.7in
• iPad Pro 11in
• iPad Air 2
• iPad Air 3
• iPad fifth generation
• iPad sixth generation
• iPad Mini 4
• iPad Mini 3