From this Findmypast page you can browse the Leicestershire parishes which have parish register transcripts online.
From this Ancestry page you can browse the Leicestershire parishes which have parish register transcripts online.
For both of the above sites, a subscription is charged. Transcriptions of these records may also be available free of charge on the FamilySearch website.
A further collection of online source references will be found on the county page for Leicestershire.