What kind of graduate program are you talking about?
A PhD program, or a terminal master’s degree program?
In engineering, or in some other field?
Admission and funding may work very differently depending on the kind of program.
Overall 4 year or 6 year graduation rates can be found in each school’s Common Data Set (section B), or on web sites such as Kiplinger’s (http://www.kiplinger.com/tool/college/T014-S001-kiplinger-s-best-values-in-public-colleges/index.php). TAMU’s 4 year graduation rate, according to Kiplinger’s, is 51%. Purdue’s is 42%. These are overall graduation rates. The rates for specific majors or schools/divisions may be significantly higher or lower than the overall rate. If you know exactly what your kid wants to major in, you might want to contact admissions or the department chair for graduation rates in that program.