Hey,

Assam CEE 2018: Assam Science and Technology University will be responsible for the conduction of Assam CEE 2018. The combined entrance examination of Assam CEE 2018 provides admissions to all eligible candidates into the undergraduate engineering courses offered by the participating institutes. The offline exam will be held on April 29, 2018 for all registered candidates. The application form of Assam CEE 2018 will be available from March 1, 2018 onwards. All candidates who wish to pursue their engineering studies in the participating institutes of Assam CEE 2018 will have to register themselves and attempt the entrance examination.
Link to Article: https://engineering.careers360.com/articles/assam-cee

NATA 2018 - Council of Architecture (COA) will conduct National Aptitude Test in Architecture (NATA) on April 29, 2018. The exam is conducted for admissions to the 5 year Architecture programmes offered across the country. The exam will be held in two parts with Part A being online and consisting of Maths & General Aptitude and Part B which is offline consisting of drawing questions. Candidates can fill the online NATA application form till March 2, 2018 if they meet the prescribed eligibility criteria. Application fees of Rs 1800 (Rs. 1500 for SC/ST category) have to be paid to submit the application successfully. 
Link: https://engineering.careers360.com/articles/nata

Till now, there is no update regarding change of date of either of the two exams. If the date is not changed then students will have to priortize between NATA and ASSAM CEE based on their aspirations and college preferences. Keep following our website - in case of any official notifications, we will update our viewers.

All the best for your preparations!