hello, 

see, at first you must have a proper goal of what you want to do. now, SNU SAT is the shiv nadar university entry test, UPSEE being the common entrance for all the engineering colleges in UP whereas IPU CET is for indiraprasth. 

now i would personally suggest you to go for UPSEE as this may help you target more colleges where as other 2 would to some extent limit you. 

however the preparation of all the 3 would be almost same so you can apply for all 3 exams and then see under which cut off you lie. 

refer to links for info 

https://www.careers360.com/question-snusat-syllabus-0

https://engineering.careers360.com/articles/ipu-cet-syllabus

https://engineering.careers360.com/articles/upsee-syllabus