How to start designing with Altera FPGAS? Any free FPGA design software is available? Earlier designed Actel FPGAs for SPACE applications. Staying in Bangalore, any point of contact available if any issues occur while designing?

You can download and install the quartus lite version.

https://www.intel.com/content/www/us/en/programmable/downloads/download-center.html

I would strongly suggest you go through all the online training before you start the design.

https://www.intel.com/content/www/us/en/programmable/support/training/course/odsw1110.html

Make sure you click on the following courses as well.

If you have more question after attending the training. You can post it to forum.

any further question?