When joining multiple tables the output of each join logically forms a virtual table that goes into the next join.
So in the example in your question the composite result of joining the first 5 tables would be treated as the left hand table.
See Itzik Ben-Gan’s Logical Query Processing Poster for more about this.
The virtual tables involved in the joins can be controlled by positioning the ON
clause. For example
SELECT *
FROM T1
INNER JOIN T2
ON T2.C = T1.C
INNER JOIN T3
LEFT JOIN T4
ON T4.C = T3.C
ON T3.C = T2.C
is equivalent to (T1 Inner Join T2) Inner Join (T3 Left Join T4)