1.If you are fabricated in false 498-A cases, first you should get yourself acquitted from such charges. Defamation case can be filed against your in-laws after that.
2.If you do get published something against your in-laws through any media before your rebuttal of charges,the barrel of defamation may be opened against you(you all know the biasness of Indian laws in such matters) and this is what you surely want to avoid.
3.If you have mere apprehension of being fabricated in 498-A,the best way,I believe,to show your neighbors/distant relatives/in-laws relatives who you are on good terms, the reality happening in your 4 walls.I won't elaborate further on that way.......
4.Use Media only to show the generalization of abuse of 498-A provision and it depends upon you how well you tackle media persons.Don't talk about your case in media specifically.
Hope It's enough from my side covering possible answers to your question.
you are free to seek experts advice on this matter further.They can guide better.