Dear Sir,
1) LTCG would be 5.08 lacs and LTCG tax would be 1.05 lacs
2) Yes in the ITR of F.Y. 2017-18 (A.Y. 2018-19) due on 31.07.2018.
3) Assuming equal share with your father, your LTCG would be 2.54 and LTCG tax would be 0.52 lacs.
Note-If you have income from any other source which is less tha max. threshold limit then you will get the benefit of shortfall from the LTCG. No deductions u/s 80C to 80 U are allowed from LTCG.
Thanks