What is full inclusion? Some states see it as simply putting all the 'disabled' bodies and minds in the same physical space as the other students. Unfortunately, this type of inclusion does not enable an intellectually challenged individual or provide them with the support they need in a classroom.
Look for a classroom where special needs students are engaged in similar activities as the other children in the classroom BUT not necessarily doing the exact same assignment. Modifying a lesson plan may be time consuming initially for the teacher but will benefit the intellectually challenged student as they move through their classroom.
Not every classroom is equipped to work with a student with intellectual disabilities and may need some tweaking in order to make it 'disability friendly.' I still remember when my daughter, now an adult, was in a Child Development Class in high school. The students were assigned oral presentations on color blindness. Unfortunately the teacher wasn't supervising things too well, and my daughter's assignment? The genetics of color blindness! This for a student who had never had a class in genetics or high school biology and who had no idea what genetics entailed. What it was was a major challenge!
Also when we had made the decision to put her in this classroom (she had never been in an inclusion classroom) we did not take into consideration that she had never had to speak in public or write even short papers. We just thought it would be useful information for her to have when she graduated from high school and moved into the adult world. This was a learning experience for my daughter, for me, and for the local school system. Fortunately that was over ten years ago and schools have evolved. Work with your child's special education group to design an IEP program for them that will provide them with a learning experience that is tailored to their own special needs as well as provide positive inclusion experiences.