Hello Aspirant,

Yes, the electronic marksheet of class 12th which is present in your Digilocker can be submitted temporarily to the colleges for admission purposes but note that, those digital certificates/marksheets present in your Digilocker is only valid for electronic purposes but for physical purposes you have to submit either original or xerox copy of the physical certificate/marksheet. As you have mentioned that you don't have the physical/original marksheet right now so you can use your digital marksheet just for confirming the  seat in college and remember to submit it later.

I hope this information helps you.

Good Luck!!