It was based on Indira's life and I don't feel anything wrong was shown to defame her. 

Well, Neerja was too good and inspiring. Though the real life protagonist could not be live. A very inspiring story.

I even liked Bhaag Milkha Bhaag, and the legend himself enjoyed the movie a lot

Babu saroj wrote:Well I don't think that there is anything wrong in that, actually if a film is made on a person who is alive then I think he must have done something great for the country that why a film is made in his or her honour.

Not necessarily ! Films have been made on smugglers, Criminals and murderers ..

How was Aandhi based on Indira's life is not clear.

Obviously there was a similarity in Aandhi to her life which made her feel on the defensive or  else why did Indira Gandhi see red and ban the film ? The differences between the couple who later separate and the father taking advantage etc etc ..

http://www.oneknightstands.net/revisiting-gulzars-aandhi/