Reg. recommended Solr 6.x version to use in prod

[Hari Baskar]

Hi, 
  We are currently running Solr 5.1 in production. We do not use SolrCloud now 
. We plan to move to 6.x and use SolrCloud. Any specific recommendations on the 
recommended Solr 6.x version to use in prod. We are open to reindex all the 
collections during this migration. Outr major use is full text search. We use 
data import handler with SQLEntityProcessor and Apache tika to index documents.
-Hari