Hello Deepa, don't worry you can make changes to your application, even after the final submission. According to the official website of Central Teaching Eligibility Test ( CTET ) , the candidate cannot make any changes to his/ her particulars after they have submitted the application and paid the fees. The changes to the particulars can be done only from 14 March 2019 (Thursday) to 20 March 2019 ( Wednesday), this is the time period for which the correction window opens. Corrections has to be done through an online medium. It clearly mentions that no further requests for editing the application will be entertained afterwards.
The candidates can make online corrections only in the following details:
1. Name
2. Father's name and Mother's name
3. Date of birth
4. Category
5. Differently abled category
6. Paper opted (i.e. Paper 1 or Paper 2)
7. Subject for Paper 2 (i.e. the paper for qualifying in class VI - VIII category)
8. First choice of Centre
9. Language 1 or 2 opted
10. Address of correspondence
11. The name of Institution/ University/ college from where the candidate obtained their B.Ed Degree/ Diploma in Elementary education etc.
This facility will be provided by the authorities only once so should be used wisely.
The board has also mentioned very clearly and strictly that it will not be responsible for the consequences in case any changes/addition/ omissions are not accepted. Even if you had any particular reasons to change it.
Also any corrections to the particulars will not be accepted through an offline mode like fax/ application or even an email etc. And if the specified date for correction of these particular is over, no further requests will be entertained.
Please note that your admit card will be provided to you by the last week of June 2019. Also, your exam is on July 7, 2019.

In case you are applying for both the levels ( class 1 to 5 and class 6 to 8 ) then you must appear in both the papers.
For any further queries about the paper download the Information bulletin from the official website (link given below)
https://ctet.nic.in/CMS/public/home.aspx
All the best!
I hope this helps.