After successfully migrated from Magento 1.x to 2.x I am getting issues with Indexer, Check below screen.
(I need to Show products on frontend So, re-indexing is must)
Please Help Thanks in Advance.
As stated in the comments, most probably you imported some tier prices for at least a product for a website that does not exist.
To fix this you have to identify the rows in the table
catalog_product_entity_tier_price that have in the column
website_id a value that is not present in the table
A rough query could be
SELECT * FROM catalog_product_entity_tier_price tier WHERE website_id NOT IN ( SELECT website_id FROM store_website )
I'm sure this is not optimized but it should work.
To delete the rows if any just change in the query above
SELECT * with
This is not tested and I might be wrong so please backup your db first.
If there are rows and you delete them, try reindexing again.