Hi Parth,
You're talking about the long flex cable that goes between the LCD and the motherboard, right?
If that's the case it should be fairly straight-forward. I'm guessing you already have the screen off; otherwise it wouldn't have broken, so you probably know how to do that part.
Once the screen is off, you just have to remove the rear cover to get to where the LCD is plugged into the motherboard. Basically just take out a zillion screws, take off the back and flip it over. That whole procedure is shown in this video teardown; all you have to do is follow it up to about the 13:43 mark.
[link|https://www.youtube.com/watch?v=H6ZM_arR_94|Samsung Galaxy Tab A 10.1'' (2019) SM-T515 📱 Teardown Take apart Tutorial - YouTube|new_window=true]
And of course you'll need a replacement flex cable; you can find those all over the place; eBay, Amazon, AliExpress, etc. Here's one of the first ones that came up on a search.
[link|https://www.amazon.com/Pantaohuaes-Flex-Cable-Galaxy-SM-T515/dp/B08C7V9H7D|Amazon.com: Pantaohuaes LCD Flex Cable for Galaxy Tab A 10.1 (2019) / SM-T515 / T510 : Electronics|new_window=true]
Good luck with your repair; let us know how it goes!