Greetings,

That is not an issue if there is a academic gap you can just provide your 10th and 12th marksheet. In case if some institutions ask reason for the gap and some may ask for a certificate stating what you were doing in that time gap only then you have to provide the certificate for the gap.

If there is a gap between your +2 and joining for degree then you will need a certificate for the academic gap.

hope this is helpful

thank you