Calls automatically disconnect after 2 mins on my iPhone

82% is close to Apple's recommended level of 80% for having the battery replaced. The weak, aging battery may not be providing sufficient power to the iPhone's antenna to connect with cell tower signals. Have the battery replaced:

iPhone Battery & Power Repair

About genuine iPhone batteries

Repair Provider Verification

(Articles found by searching Apple's Knowledge Base.)

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yashukaushik ~ What model of iPhone is it?...

Settings > General > About > Model Name

And what version of iOS is it running?...

Settings > General > About > iOS Version

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Does your iPhone SE still have its original battery?

And what's the Maximum Capacity % here?...

Settings > Battery > Battery Health & Charging

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