Does ISRO take in applications with a foreign degree written on it

Yes,ISRO or DRDO/HAL etc accept foreign degrees.
Please visit ISRO website for the openings.
Please do PG in good specializations in Aerospace/Aeronautics and this help you to get the jobs.
There are private companies in India working on Aerospace like GE,Boeing,Honeywell,Eaton,Goodrich Aerospace,UTC etc.
Do your Masters project/internship in aerospace companies like Boeing,Rolls Royce,Airbus etc in Europe and this will help you to get jobs in MNCs working on aerospace field.

There is no restriction on employing people obtaining post graduation from foreign countries for jobs in ISRO. But the degree you are obtaining should be from a University which is recognised by their country and it should be on par with our M.Tech. So choose a good University and a good specialisation in the concerned subject and do the needful. The ISRO will be giving advertisements for recruitment. Keep watching for their announcements. They never entertain applications which are coming without their notification. Best of luck to you.

The Master degree obtained from a recognized university of the United Kingdom will be accepted by ISRO. In fact, during the initial days of ISRO, most of the scientists used to join with foreign degrees.

So, don't worry. Keep track of the vacancies in the suitable field advertised by ISRO (from the Website and also from the Employment News), and apply for the post.

It may appear surprising but it is true that many professional degrees obtained in foreign countries especially in fast track mode or correspondence mode are not recognized in India.

Association of Indian Universities (AIU) is the apex body in devising norms of equivalence between the foreign degrees and Indian degrees. As per those norms, many courses are not considered equivalent in India when it comes to applying for a job. The organization like ISRO or any other PSU or Govt department harp on the directions of AIU in such matters.

One has to see the detailed norms of AIU along with latest relaxations, if any, to find out exactly the fate of his earned degree overseas in connection with any job in India.

Before you take any step for the perusal of Masters - degree from UK, you should confirm the same from the websites of ISRO. In getting a job in India with the foreign qualification, becomes difficult sometimes because of non- acceptance of such degrees from UGC angle.
ISRO being a central government organisation follow the rules and regulation of Association of Indian University and hence such guide - line may be looked into prior to perusal any foreign qualification.
Time to time, the rules of AIU undergoes revision and hence updating of the same would be a boon on your part.