How can my son get admission in top engineering colleges in Indian or abroad? Should I change my son's board from ICSE to CBSE?

As per the official information by the University of Iowa, it is not really mandatory to apply with a SAT score. The students can sumbit the application without it. Although, if the students voluntarily wish to do it the can as it enhances the overall student profile and also raises the admission chances. 

Students can aim for a University of Iowa SAT score of around 1250 to 1350 as its considered really good. 

For undergraduate admission, Humboldt University of Berlin Does not require submission of Act or SAT marks are necessity. You have to provide a German University Entrance Qualification which can be obtained through the German Arbiture or equivalent qualification. But the university also looks into other factors for admissions like strong academic background, English language proficiency requirements, LORs, personal essays extracurricular activities etc.

No, ACT or SAT scores are not considered a mandatory requirement for international students willing to take admission in UG programs available to them. The university mainly admits students based on academic and English language requirements. The university mandates the completion of the application form by submitting all the necessary documents as required by the programs candidates apply for. Generally, students need to submit academic transcripts along with English language score cards and additional documents like LOs, SOP, CV or resume, or any other specified requirements.

The Harvard University does not prefer one test over the other; the university accepts either the SAT or the ACT. The university also encourages applicants to submit the test that best highlights their academic strengths.

An ACT score of 26 is roughly equivalent to an SAT score between 1230 and 1250. This places both scores well above the national average.