"Every Regular Grammar has a Right linear grammar and this is LL(1)"
Conditions for LL(1) :
1) unambiguous CFG .
2) left factored.
3) not left recursive.
If a grammar is Right linear then it is Not left recursive for sure.
But if the Right linear grammar is like this,
$S$ $→$ $aA$|$a$
$A$ $→$ $c$
Then this is not left factored grammar, hence Not LL(1), but there are some which can satisfy all the conditions and can be LL(1).