Hi, my macbook pro 2012 won't turn on, no charge, not even displaying battery indicator. Is it the battery problem or hardware?

Hello bishuadarsh,

Does the Mac Book Pro power on when connected to a power source? If your Mac doesn't turn on - Apple Support

If it will power on with a power source but not on battery power this is likely an issue with the battery which has possibly just reached it max lifespan. If not, then you are likely correct that you have a hardware or startup software issue.

Contacting Apple Support will be your best resource in either case. But, you can get some more information if you are able to power on the computer.

Get help with your Mac notebook battery - Apple Support

“Check battery health

You can check the health of your battery in Battery preferences or the Battery status menu:

• In macOS Big Sur, choose Apple menu  > System Preferences, click Battery, select Battery in the sidebar, then click Battery Health.
• In macOS Catalina or earlier, hold the Option key and click the battery icon in the menu bar to reveal the battery status menu.

You'll see one of the following status indicators:

• Normal: The battery is functioning normally. 
• Service Recommended: The battery's ability to hold charge is less than when it was new or it isn't functioning normally. You can safely continue to use your Mac but you should take it to an Apple Store or Apple-authorized service provider to get your battery evaluated.

To get service on your battery, contact Apple."

I hope this helps.