Mailing Hard Copy Transcripts

I had some doubts regarding mailing transcripts all help is appreciated

  1. If I submit stamped photocopies, is that okay as I need to send transcripts to two more universities?
  2. I am currently in 12th grade Indian Curriculum, and I have changed schools after 10th grade i.e. for 11th and 12th grade I have gone to a different school. So when mailing transcripts do I need to send transcripts two times? Couldn’t my current school attest 9th-10th grade transcripts with 11th grade? As I am an International it costs a lot to send a courier, therefore it would help me a lot if I could send them all in one package.
    Thanks a lot