LR 6 to 7.2 or newer Upgrade

What's more important: 

• Support for modern camera & computer equipment? 
• Or clinging to legacy software? 

That's a question only you can answer.

If the former is important, you can get a $10/month Photography Plan that includes the following:

• Photoshop CC and Photoshop on iPad
• Camera Raw
• Lightroom on desktop, mobile and the web
• Lightroom Classic
• Portfolio website + hosting
• Adobe Express (free starter plan)
• Bridge
• 20 GB cloud storage (upgradable to 1 TB).
• Free upgrades to paid subscribers

https://www.adobe.com/creativecloud/photography.html

no.  6.14 was the last  lr 6 update.