Transact SQL :: How To Count Where Two Tables Multiple Columns Match

There are two tables

TABLE 1 (NAME - Groupseats)

id session course groupcode sub1 sub2 sub3

1 2015 ba1 137 HL EL Eco
2 2015 ba1 138 EL SL HS
3 2015 ba1 139 SL EL His

From this table i use to admit a student and select their choice of group simultaneously all the subjects associated with GROUP is save on another table.

Here is the TABLE 2 Structure and sample data:

table 2 (NAME - tblstudetail)

id studentID session course sub1 sub2 sub3

1 15120001 2015 ba1 EL SL HS
2 15120002 2015 ba1 HL EL Eco
3 15120003 2015 ba1 SL EL His
4 15120004 2015 ba1 HL EL Eco

AND so no..........................

Now i just want to COUNT the Number of Groups Filled in tblStudateil.