Malayalam letters not displaying properly in libreoffice 5.1

Some letters( for example letters ല and ല) which are to be combined are not displaying correctly. It displays correctly in this screen as ല്ല, but not correctly in libreoffice 5.1.

I have pasted your sample (ല്ല) into LibreOffice Writer 6.2.5, LibreOffice Writer 5.4.2 and Microsoft Word 2010. It looks the same everywhere. So what is the problem? Read these guidelines and ask a good question. Or, perhaps, you just need to upgrade LibreOffice.

What font are you using? Also, it may depend on the rendering engine (for example Graphite), although that can depend on settings.

I have even less information on Malayalam than on Telugu, but see my answer to this question. Matters may be related.