yes it will be taxable u/s 56(2)(vii) because as per amendmends made in Finance Act 2012 HUF can take gift from its members only not from members relatives..
your mother does not form part of your HUF.. in that case it is advisable that your mother should give gift to you and on the other hand you give gift to your HUF..
both the transictions will be exempt u/s 56(2)(vii). but second transiction will be subject to the provisions of sec 64.. clubbing of income..