@raghav_77 ,
As per the certification handbook , it's not
Splunk Certification exams are not open‑note. This means that any reference material (notes,course documentation, access to Splunk Docs or Splunk Answers, etc.) is strictly prohibited. Both on‑site and online proctors are trained to identify unauthorized materials or behavior. Any perceived violation of the closedbook policy will result in automatic failure and forfeiture of registration fees.
Reference :
https://www.splunk.com/pdfs/training/Splunk-Certification-Handbook-v.8.31.2018.pdf
https://www.splunk.com/pdfs/training/Exam-Registration-Tutorial.pdf