There is no official press release or notice from the Ministry of Home Affairs on the banning of display of Shiva lingam in public.
A Shiva lingam, sometimes referred to as linga or Shiva linga, is an abstract representation of the Hindu deity Shiva in Shaivism. It is typically the primary devotional image in Hindu temples and shrines dedicated to Shiva.
On investigating the same, we could not find any press release or an announcement from Ministry of Home Affairs or an official statement from Union Home Minister Amit Shah on his social media handles, or from his office.
Since there is no evidence to prove that the use of Shiva linga is banned by MHA in the public, hence the claim false.