Diploma

you have to decide which country you want to do. For aeronautical engineering you try in Ireland or in UK. You do get BE hons that is inclusive of one year internship. if you have practical experience only you can write EASA. exams and become certified aeronautical engineer.
you have to do IELTS. and apply directly online on University website. You also get the help education agents and apply through them, who will guide you for visa processing.

Admissions to recognised polytechnic colleges under DTE in almost every state will be made on the basis of marks scored in the 10th standard examinations.

Yes they do, for detailed information click on the link below :
http://www.ymcaust.ac.in/index.php/admissions/courses/b-tech-b-tech-leet

Xlri, IIM Udaipur, IIM calcutta, ISB Hyderabad, Spjain, Nmims, IIM Bangalore, MDI gurgaon, IMT ghaziabad , KJ somaiya, Sydenham, Welingkars, XIMB, IIM Ahmedabad.

2 year experience and u get job