Is there a way to limit output of Tags related to an entry? I've checked it with documentation but, tag model doesn't have limit() property as entries have. 

Wondering, If there is any way around to achieve it?
A limit doesn't make sense on a single element model. But all ElementCriteriaModels have a limit parameter and for craft.tags it is documented here.

To limit the tags related to an entry via a Tags field don't use the shortcut syntax:

{% set tags = entry.tagsFieldHandle %}


But modify the craft.tags ElementCriteriaModel instead:

{% set tags = craft.tags({
    relatedTo: { sourceElement: entry, field: "tagsFieldHandle" },
    order:     "sortOrder",
    limit:     null
}) %}