hi harshita,

To get admission in ISRO after B.Tech you can give ISRO Recruitment exam which is conducted mostly in the month of april.

ISRO Recruitment exam has the following eligibility criteria:

• Candidates must be B.Tech/(Diploma + B.Tech (Lateral Entry) qualified or equivalent qualifying degree in first class with an aggregate minimum of 65% marks or CGPA of 6.84 on a scale of 10.
• The average of all semesters will be considered for the purpose of checking minimum aggregate of 65% or 6.84 out of 10 CGPA
• Candidates currently in their final year of qualifying degree are also eligible to apply, provided their final degree will be available by July 31 and secure an aggregate of 65% marks or CGPA 6.84 on a scale of 10.
• Candidates who have passed M.Tech with B.Tech are eligible to apply provided their B.Tech marks meet the eligibility specified above.
• Candidates who have studied Integrated course of B.Tech and M.E/M.Tech are also eligible subject to production of Graduation certificate for B.Tech separately in first class with an aggregate minimum of 65% marks or CGPA 6.84 on a scale of 10.

For more FAQ regarding ISRO Recruitment exam : CHECK HERE (https://www.isro.gov.in/sites/default/files/frequently_asked_questions_and_answers_cepo_2019.pdf)

I hope this answer will help!!
All the best for the future!!