@Upender Kumar I am assuming the excel you are referring to contains the values e.g. first name, last name etc. and these must be defined as variables on the record producer.
In order to create lifecycle event cases in bulk, I would recommend you to create a fix script in Human Resources Lifecycle events scope.
1. As a first step, you would need to parse the excel sheet which can be done using GlideExcelParser here is the reference to a thread which explains this API using an example very well https://www.servicenow.com/community/developer-articles/you-dont-know-sn-apis-glideexcelparser/ta-p/...
2. In the second step, you would need to create the records using your record producer programmatically. Unfortunately, CartJS API is of no use in this case as it only works on Catalog Items and not record producer. Here you need to use solution provided by the author in this post https://www.servicenow.com/community/itsm-forum/how-to-trigger-change-workflow-record-producer-from-... here author Daniel A-C has suggested a Script Include for this purpose which will help you to create records via the record producer programmatically.
I hope by joining the pieces together you will be able to create Lifecycle events cases in bulk.
Hope this helps.
