Any person in India, is free to change their name and their is a process that has to be followed while doing this. You have changed your name and you have also updated it in the records, now if you want to study abroad, your name in the certificates must be same as those in your other official documents such as PAN Card and Aadhaar card.
You must change the name in these certificates also and only after this, you will be able to get the admission in your college abroad. As you have updated the name in other documents, you can use them as proof and can get the name corrected in your marks card and certificates. You need to aproach your university or the board with which your college is associated and you can get the name rectified . You can request them to issue a new certificate along with the marks card and can apply for abroad education.
You can request theboard for the urgency of these documents as a delay will impact your admission. If the board refuses to do so, you can file a case in the court against the board. You can provide the proof of name change that is the newspaper clipping, notification in the gazzette and the other documents.
Reference: Article 21 of the Indian Constitution