I wish when the form(FORM4) is opened, the user should be promted to select YEAR, TERM, GRADE,STREAM and when the user selects then that active should be shown as you add students.
1-->If you want to add students to Year/Term/Grade/Streams you have set up your forms wrong. 2-->Looking at your relationships, I think you've overcomplicated this and have set up your tables incorrectly as well.
1: Main forms/subforms are used for 1-many relationships. The main form represents the 1 side and the subform holds the many. As it is now your main form is based on students and the subform is for the year/term/grade/stream. It sounds like you want 1 year/term/grade/stream and have many students. In that case your main form should be based on year/term/grade/stream and the subform should be streamstudents.
2: You've got a ton of tables that needn't exist. Tables with only 1 real data field (autonumbers are not real data--they are used internally by the database) shouldn't exist. That's especially true when you are just storing numbers in those tables. tblTerms is just storing numbers, although as text (Term 1, Term 2, Term 3). Instead that data should just live in the next table up the hierarchy, tblTermYears. Instead of a foreign key to tblTerms in tblTermYears (which itself is a number), just store the number of the term in tblTermYears and do away with tblTerms. Same applies to tblYears, tblGrades and possibly tblStream.
Now, since both tblYears and tblTerms as well as tblStream and tblGrades shouldn't exist that calls into question the need for tblYearTerms and tblGradeStream. Why can't tblTermStreams be like this:
tblTermStreams
TeamStreamsID, autonumber, primary key, same as now
ts_Year, number, this will hold the numeric value of the year (which now ultimately comes from tblYears)
ts_Term, number, this will hold the numeric value of the term (which now ultimately comes from tblTerms)
ts_Grade, number, this will hold the numeric value of the grade (which now ultimately comes from tblGrades)
ts_STream, number or text, this will hold the value of the stream (which now ultimately comes from tblStream)
ts_Select, Yes/No, don't know what this does but it remains if necessary
That gets you to 3 tables, from there it should be easy to set up a main form based on tblTermStreams, a subform on tblSTreamStudents and assign students to a termstream.