Hello Aspirant,

Provisional Seat Allotment Letter is having the information about which institute you got admission with the branch and in which round of the counseling. It also contains the information of the reporting center and date and time of Document Verification to done by the candidate. 

Candidate Undertaking is done by the Institute, in which you have to choose whether you want to  Freeze/Float/Slide your seat in the further rounds of the counseling and accepting the terms and conditions of the Institute.

Hope this information is helpful.