This depends on what you want. An OG of 1.090 produces ~11.5% ABV, which is a nice table wine, and most yeasts will ferment that dry.
I generally target the OG between 1.080 and 1.100, with 1.090 my preferred target.
Following is a Specific Gravity vs. Potential Alcohol table. I've seen variations on the table, but this one is good enough for you to gauge what the ABV will be.
SG PA
1.070 8.9
1.075 9.4
1.080 10.2
1.085 10.9
1.090 11.5
1.095 12.2
1.100 13.0
1.105 13.7
1.110 14.2
1.115 15.0
1.120 15.7
1.130 17.1
1.135 17.8
1.140 18.4
Thanks so much for the very quick and insightful reply.. Reason I asked is I have read somewhere that people advise to add your sugar slowly.. This is what is confusing me, do I need to add more sugar or is it enough, as I had initially only added 1 Kilo of sugar... Moreover, some of the must stills look pulpy and has not totally disintegrated..